First of all, this is NOT a review of any sort, not even a field test. I am merely sharing my experience with the Canon system in general and 450D and 55-250 IS lens in particular.
Dawn over Kaziranga
Recently, I had an opportunity to try out the kit at Kaziranga National Park, Assam. Though we stayed in the park for only two days and were 'inside' the park for only 3-4 hours, We saw a great deal of wildlife.
One-horned Rhino, Kaziranga National Park
The 450D felt very comfortable in my hands. It felt lot lighter than my Pentax K10D and I liked this fact. Its viewfinder was somewhat darker than K10D, but I didn't have much issue in focusing manually. Its LCD was bigger than K10D but was little confusing. Image looked very dark in the LCD than on monitor. I never used the Live view mode. The very fact that I have to go through settings to change from LV to VF mode didn't impress me at all..(please let me know if there are any shortcuts to do so)..
I liked the dedicated ISO button in the 450D. It enabled rapid change of ISOs as and when I needed and I needed to change ISO very frequently. Auto focus operation was super quiet. almost SILENT. Focus was fairly quick too. The fact that it was so silent also made it appear even more quick. Coming from manual-focus-lenses background, this was the first AF tele (provided you call 250mm a tele. On APS-C, it certainly is.) I ever used and I was in awe of the AF to say the least. Initially, I had difficulty in shooting birds in flight with the combo but soon learnt the beauty of Al-servo and the central cross-hair AF point. I could effortlessly track every bird I was able to get inside the frame. Once again, I was limited by my own self. IQ wise, 450D was excellent. I used it most of the times at ISO 800 and at times at ISO 1600. Seriously, there are many things which we hear on forums and reviews which are to be simply forgotten during actual field work. High ISO is one of them. How am I to avoid ISO 1600 if the camera meter shows 2" even at ISO 1600, wide open? Many times I had to use EV to increase shutter speed by increasing ISO even further. Here I wished Canon had 5 stops of EV instead of 2. Especially considering the over- exposure Canon bodies normally cause. This brings us to the only serious issue I had with Canon system- the one which cost me at least half a dozen of well taken images- WASHED HIGHLIGHTS. I had heard from most of the Canon users that Canon bodies over expose slightly and hence, one should keep the EV at -2/3. I invariably had to keep it from -2/3 to -2! Being a user of Pentax, which is (in)famous for underexposed images, I was never bothered by washed highlights before this and I didn't even know it until I saw the images on monitor. Damn. I had to shoot jepg because there weren't many memory cards provided with the camera and we hadn't taken laptops for security reasons. The images had appeared darker in the LCD which refrained me from using extreme negative EV. I think shooting RAW would have solved the problem. Thus, this in no way count against the camera as I should have, following John Shaw's guidelines, calibrated the meter before use or at least shot in RAW.. I didn't fiddle with the camera much and used it only in the field. Hence, I'm sure there are many more tit-bits which I don't know of.
I liked the dedicated ISO button in the 450D. It enabled rapid change of ISOs as and when I needed and I needed to change ISO very frequently. Auto focus operation was super quiet. almost SILENT. Focus was fairly quick too. The fact that it was so silent also made it appear even more quick. Coming from manual-focus-lenses background, this was the first AF tele (provided you call 250mm a tele. On APS-C, it certainly is.) I ever used and I was in awe of the AF to say the least. Initially, I had difficulty in shooting birds in flight with the combo but soon learnt the beauty of Al-servo and the central cross-hair AF point. I could effortlessly track every bird I was able to get inside the frame. Once again, I was limited by my own self. IQ wise, 450D was excellent. I used it most of the times at ISO 800 and at times at ISO 1600. Seriously, there are many things which we hear on forums and reviews which are to be simply forgotten during actual field work. High ISO is one of them. How am I to avoid ISO 1600 if the camera meter shows 2" even at ISO 1600, wide open? Many times I had to use EV to increase shutter speed by increasing ISO even further. Here I wished Canon had 5 stops of EV instead of 2. Especially considering the over- exposure Canon bodies normally cause. This brings us to the only serious issue I had with Canon system- the one which cost me at least half a dozen of well taken images- WASHED HIGHLIGHTS. I had heard from most of the Canon users that Canon bodies over expose slightly and hence, one should keep the EV at -2/3. I invariably had to keep it from -2/3 to -2! Being a user of Pentax, which is (in)famous for underexposed images, I was never bothered by washed highlights before this and I didn't even know it until I saw the images on monitor. Damn. I had to shoot jepg because there weren't many memory cards provided with the camera and we hadn't taken laptops for security reasons. The images had appeared darker in the LCD which refrained me from using extreme negative EV. I think shooting RAW would have solved the problem. Thus, this in no way count against the camera as I should have, following John Shaw's guidelines, calibrated the meter before use or at least shot in RAW.. I didn't fiddle with the camera much and used it only in the field. Hence, I'm sure there are many more tit-bits which I don't know of.
Tusker, Kaziranga: Plenty of washed highlights in this image, toned downed a bit.
Overall, I liked the camera but is it worth 38k? certainly not. I won't give more than 20k for it or any camera in this class, especially when one can get a 40D for 39k. I used the 450D exclusively with the 55-250IS lens even though I was provided with the 18-55IS lens. 55mm is wide enough for most of the landscape shots I usually take on field. However, I think ideal focal length for the job would have been an image stabilized 28-300/5.6 or a 35-350/5.6..I would have preferred the latter. Canon did make these lenses, but they were too expensive and heavy for the target users and purpose they fulfilled. All shots of birds were taken at 250mm. Mammals required the lower focal lengths. IS was God sent. It gave me sharp images at 5.25 stops more than the normal shutter speed when I shot at the wider end of the lens. At tele end, I could get about 2.5- 3 stops advantage. IS clearly substituted tripod at least for this tour. Of course there were opportunities which only tripod could have taken, but they weren't many. I am planning to buy this lens and a used 400D.
People asked if 250mm is enough? Well, I performed a simple exercise- I used Juza's focal length calculator with references being 250mm on a 10 MP Canon APS-C slr and a 720 X 480 canvas. With the help of this calculator I found out that if I crop a 10 MP image to 7 MP, I will get a field of view (FOV) of a 300mm lens. Similarly, I will get FOV of 400mm, 500mm and 600mm lenses if I crop the image to 4 MP, 2.5 MP and 1.7 MP. I know 1.7 MP sounds too small. But I mave made excellent 12 X 8 prints of images as small as 1.26 MP. My only concern is of IQ. Yes, IQ isn't the best at f5.6 but improves dramatically through f8 and finally at f11. In Pune, the weather is mostly sunny and I am able to usually shoot at f11-16. Its weight is perfect for my needs- a light weight, in-expensive lens which would remain with me 24/7. Add the close focusing ability so essential for dragonfly, butterfly and reptile shots and you have the truely wonderful all round lens required for wildlife documentation. Seriously, 55-250 IS lens is one of the best ways one can spend 13.5k. :)
The 400D decision is based on the fact that I liked the 450D. Yes, they are two different cameras but belong to same class. Quite similar Viewfinder, ISO performance, fps, negligible weight difference etc. I never used the Live view and the bigger LCD didn't quite impress me. The minor differences are not field relevant. The only major difference IMHO is 2 extra MPs, which are enough to make a difference between the FOV of a 400mm lens and a 450mm lens (on 35mm film). That, however, isn't worth the extra cash. The 400D and 55-250 make an inexpensive kit which I can carry around all the time without stress of lugging $$$$ everywhere I go. The money saved by opting for such an inexpensive kit will go for a decent laptop which will replace my 11 year old desktop or may be as saving for 100-400 or a 400/5.6 in near future.
Few images from the combo..
A few images from the trip:
Wild boar, Kaziranga
Rhino, Kaziranga 
Hog Deer, Kaziranga
Safari 
Sunset, Kaziranga 
Moonrise over Kaziranga
