Any opinions on the Konica/minolta Dimage Z2 vs Z3

[Merri]

I want t a camera with a good optical zoom where I can take pictures closely at a concert for kids. It won't be as dark as a nightclub but it won't be like daylight. I also want the zoom to get candids of my son since he always makes faces when he knows he's having his pic taken. I need a non slr, hoping for one that is reasonably easy to learn in about a month and I'm not totally overwhelmed. Would either one handle lowlight conditions. The performers are under brighter lights. Does the IS really help on the Z3. I looked at some others K/M that have iso 800 and didn't know if I really have to go for that. Plus the price tag is getting out of range.. I'd really appreciate opinions of those who use it. I'm not a pro photograher so small things won't bother me. I want a fast camera, good zoom that can handle low light. What do you think?