But what's with grainy higher-ISO performance and low light performance, epecially when half the pic is in shadow and the rest in light.
All little cameras seems to have this issue; do you really need to move to SLR style?
It's due to the fact that compact digital cameras have very small sensors, and therefore have much smaller light receptor sites compared to the APS-sized sensors found in most digital SLRs. I don't know enough about sensor technology to explain this scientifically, but I do know the effect is to lower the signal-to-noise ratio for each pixel (since each pixel is smaller and receives less light I presume).
Even at its lowest ISO, my Canon G7 exhibited visible noise. Drove me nuts. The last time I used it was the day before I bought a Nikon D200, and this weekend I actually traded it for my grandfather's 1984 Nikon F3HP. The F3 will still be great camera 10 years from now, but the G7 won't be much more than a Wikipedia entry.
I get objectionable noise at ISO 1600 on the D200, but I don't do much concert photography, and nearly all of the other low-light stuff I do is on a tripod at ISO 100. Still, film was never that good at ISO 1600.