I just installed CHDK on my Canon A630 to check it out. It adds the ability to shoot RAW, do exposure bracketing, and other stuff. So far, so good, but it's definitely a lot slower on saving the RAW+JPG than just the JPG

One irk so far, it looks like to do exposure bracketing you have to use continuous mode, which is mutually exclusive to using the timed delay. Ideally, I'd use this for HDR on a tripod using the timer and wouldn't have to hold down the button continuously to get a three shot bracket. I don't know how this works on most DSLRs.
It can be a touch confusing having two different menu layers (it adds itself on top of the current firmware, not in place of it), but I'm sure it just takes time to adjust. I'll have to play around with some RAW vs JPG comparisons and see how it does. While the A630 doesn't have the low pixel density of an SLR, it does have a fairly low density for a 8MP P&S (21 MP/cm^2 compared to 35 on current Canon 10MP P&S and 2-3 on a DSLR).
http://chdk.wikia.com/wiki/CHDKAnyone else using it? How do you like it?