40D user here, got it for about a year already.
To me 50D is not worth the dough.
MP wise, the increase doesn't make sense to me. I never use the full pictures anyway and normally downsize the pictures. The largest I print is a bit smaller than A3.
While the rest of the features won't make the difference to me.
DIGIC IV? I think it's a marketing gimmick some how. 300D had DIGIC, 40D has DIGIC III. The company can always rename the chip to signify upgrade but just changed a fraction of the functions (at least to my opinion).
LCD? May help but I trust my eyes more as I belonged to the old time film shooter. I only use LCD to look at composition and settings/graphs.
I'll probably wait for maybe 60D or 70D instead... or unless my 40D died (choy choy!!!)
Well-said. My sentiments. They can call it "DIGIV V XTSi Turbo Plus" or "DIGIC 10TsiX Supreme" or whatever, I really don't care. All these are technology jargons that do not translate much to us consumers after the image is taken. I'm not saying DIGIC III and DIGIC IV has no difference, but can you ever look a picture or use a camera and say, Great, I love my new 50D cos it comes with DIGIC Supremo and that helps me take better pics or make my pictures more vibrant? No.
Same goes with the LCD, yes, Canon suck by coming out so late with a high res LCD (I feel they should have done it with the 40D and 450D) but that does not warrant an upgrade from 40D to 50D. More MP?? Ha, I see that more as a burden, eating up my hard-disk space unnecessarily and for me to have a much faster comp processor.
Also, the 50D's high ISO ain't a lot more impressive. I'm sure the 60D will correct that. Right now, Canon is playing an irritating marketing game by coming up with all these high MP cams (5D MkII also). For what!?
But really, it's up to you. I wonder why people tend to analyse the upgrading issue to such a detailed way, down to how you can save or lose, etc etc. It's a no-brainer question whether to buy it or not. Do you need stuffs from the 50D that the 40D can't do? Will you die without the 50D or your shots seriously need the features found in the 50D? I wonder why it's so hard to decide......
I'm ok if anyone is chasing after technology. Maybe we singaporeans are so darn rich, that could be part of the reason. If getting the latest is your cup of tea, I don't see why you should worry: "Should I upgrade to a 50D?" Just buy it! It makes you feel good. It's ok. Many people here spend $50-100k on cars like nothing even though they don't need it. An upgrade to 50D is chicken feed.
Personally, I don't find there to be any more motivation to upgrade so quickly. It's unlike say 5-6years ago where MP is so limited. Canon D30 produced 3MP. But at 8-10MP these days, you're getting a lot of real estate to print or view nice images.
I think what will really please me (and many discerning photographers) is to price DSLRs at a much affordable rate and maybe come up with a kick a** smooth pixels at high ISO. How about ISO3200 at the quality of ISO400 that we get in today's cams? That will really make my day.
It's also just a matter of time when a FF cam sells for $2k and mid ranged APS-C cams cost only $1000 or so. That will make a sweet upgrade too.