My 30D arrived yesterday and I have been playing with it ever since. How can I describe this camera and the lenses I got in one word? WOW! I knew the change from a G3 was going to be big, but I didn't realize it was going to be this big. Here are some observations I've made:
1) The auto focus is extremely fast. When I was using my G3, the main cue for me that the camera had finished focusing was when it stopped making noise. The first few shots with the 30D and my 24-105mm lens, I was waiting for the same cue. I waited five or more seconds. Then I realized the problem: the camera had focused so quickly that I didn't even realize it had finished! It used to be that the camera was the limiting factor in how fast I could take pictures. Now the limit is me. That is going to take some getting used to.
2) Focus in low light is actually possible. My G3 would hunt like mad in low light and I would be lucky to be able to auto focus at all. With a 28mm f/1.8 lens, it is no problem.
3) I don't miss live LCD preview. The optical viewfinder seems to offer many advantages, including the ability to gauge DOF and focus more accurately than on a screen.
4) The camera is heavy. I don't necessarily mean that in a bad way, either. In fact, it feels good to hold it in my hands as I walk. Around the neck for any length of time is a little difficult, though.
5) DOF is quite a bit shallower at a given f-stop than it is on a G3. I knew this was going to happen and I have to say I find it useful. It opens up a wealth of artistic possibilities.
6) The pictures just feel sharper, clearer, and more detailed. My G3 certainly produced some nice pictures and I thank it for its many years of service. However, the 30D and the 24-105mm make for a killer combination. Seeing pictures from many of you on this forum was what made me think I could get better quality photos with a dSLR in the first place and the camera has not disappointed.
7) Image stabilization is an awesome technology. Handheld shots at 1/5s? Not a problem. Not only does this help with low-light photograph of stationary objects, but I think it will open up some creative opportunities when photographing moving targets.
Overall, I do not regret the move to the 30D one bit. My G3 was and still is a nice camera that prepared me well for the move to better equipment. I feel somewhat overwhelmed with the new choices I have, but I see it as a challenge that I'm eager to take on.
Here are few obligatory
first photos taken around Palo Alto. They are nothing special really, other than being some of the first with this beautiful new device in my possession.
DSLR's and all their accessories can get quite pricey, but in the long run I do believe it will be worth it. 
