Kate check out contaxg.com which is full of Contax shooters. I have a G2 with 28/45/90 myself, and it's been my dominant camera for the past three years or so.
Don't be quick to dismiss that 45mm -- it's sharper than the 50 M-summicron. The AF will be the hardest thing to get used to, I'd wager.
Dunno about speed and noise but the G2 is faster than my Nikon, though noisier. Still when it's more than a couple of inches from you head, chances are you won't notice the sound from focusing (or even the wind motor).