I gots both: G2 with 28, 35, 45, and 90 lenses. ZI only with 35mm biogon zm.
I like both equally. Although the cameras can be used in similar fashions (esp. with AE), they really are different in use. The ZI gives you the visual feedback of manual focus with its amazing viewfinder. The G2, on the other hand, is super fast to use. I'm sure you've played with the burst mode on the thing, at four frames per second you can blow off a roll of 36 in just a few seconds. G2 has that mechanical, high quality electronic feel to it, while the ZI has more of a lightweight, nimbleness to it.
Lens wise, I couldn't tell you anything about it. I like them all 🙂