I have a Canon Powershot A510 (aka the crappycam), a Canon Rebel XT (and a Canon Elan7 35mm... but nobody cares about those anymore
What do you like/love about it?
I like the crappycam (A510) because it wasn't too expensive, it takes movies, the rechargeable AA batteries I bought last 2-3 days (unless I take movies). It's also very compact, so it's easy to throw into a pocket just in case. I also love that it makes short movies with sound, even if the quality isn't 100%. You can also edit the movies on the camera (cut the beginning or the end), which is really good.
I love the rebel XT. It's bigger and I'm afraid to damage it in extreme conditions (so I take the crappycam). I have a Sigma lens for it (the original lens is pretty garbagey) and I love my lens too. It's FAST, it's got amazing options (including a ton of manual and not-so-manual settings), the picture quality is awesome, the flash recharges quickly, the battery lasts a long time and the charger came with it... It's just great.
What don't you like about it?
The A510 is kind of slow. You press and it takes a while to shoot. When we first got it, it was one of the fastest point and shoots on the market (that's why we got this particular model). But as I use the rebel more and more, the A510 seems to get slower and slower.
Without the flash, it's quicker, but the flash takes forever to recycle.
The megapixels are low (3.2), but I'm not taking crazy art pics with it either.
The rebel.. The size is a bit cumbersome...
But you get used to it pretty quickly. Other than that, there are extra expenses, like buying a good lens, getting an external harddrive to store all the massive pics (so far my biggest pic was 8 megs, and I've taken over 8000 pics just with this camera (4000 others with the crappycam) in the past 10 months), getting a faster memory card to be able to use the camera at it's fullest potential... Oh and the flash sucks. It kind of points down, so you get the lens in the way all the time and get a big shadow.
If you want to do anything serious, you need an external flash and the cheapest is about $400...
The A510 was about $350 (including a bigger memory card and the rechargeable batteries) and the rebel with the lens, about $1300 (when you add in all the extras (spare battery, external harddrive, faster card), it's around $1700...). So there's a big difference...
But the A510 was really worth the money, IMO. It's better than quite a few of the point and shoots in its price range.