From Leica X1 to G12
I am to considering the G12 it seems like an awesome camera, but may I ask, did you consider the Panasonic Lumix LX5 since you were coming from the Leica? The LX5 seems to be a worthy competitor and I myself am having a difficult time choosing between it and the G12. I would love to hear your thoughts on the LX5 if you had tried/considered it as well.
I didn't consider the LX5 because having previously owned the LX3, and not getting on with its form and overall handling I just omitted it from my list. I also owned the GF1 and that was similary dissapointing in terms of usablility.
So I chose the Canon because of previous good experience with their products. The G12 is, as mentioned, solidly buillt, and the camera feels like a 'photographic tool' only limited by your imagination. It is a great size; fits in the hands superbly; has lovely menus and external controls, and is a joy to use.
In terms of IQ the G12 is more than adequate for what I need, and I don't feel that there are as many people who regularly print beyond A3 which is where a fair amount of discussion around IQ is located. In fact it is a paradox that a lot of today's images are only ever output for screen, a medium that surely does not correlate with the ultimate test of a cameras ability: an archival gallery print.
So, my advice (for what it's worth) is to have a look at the G12 and Nilon P7000. I prefer the aesthetic and functionality of the G12, and I don't regret getting rid of that Leica one bit.