Keep in mind that this comment is perhaps tainted by the fact I'm pretty much a Canon person these days in this type of camera.

That being said, I'd suggest the G6. The Pro1 doesn't live up to all the expectations and some of its specifications are shaky. The Pro1 is also a slow camera and we never had good luck using it with an external (550series) flash. I've personally owned both a G3 and a G5 and bought and kept both a G5 and a G6 for work. Bought a Pro1 but sold it after about a month.

The G6 is a good picture taking camera. It also has some of the best battery life I've ever seen in a camera of any type. It's got all the goodies in terms of controls and custom settings if some are perhaps a little limited(like contrast and tone) compared to some other cameras on the market. Personally though I don't find that a big deal as it is hard to really adjust a photo on two inch monitor. It shoots RAW and if you are shooting in JPEG and want to convert the image to RAW it is a button press away.

It doesn't have a live histogram, but it does have a nice tethered mode.

The zoom might be slow for some action work. The shutter lag is seemingly improved over the G5. the buffer in use is much better than the G5 regardless of some spec charts. It makes good photos from AUTO to MANUAL. And it has the great swing out and around display.

The Pan/Leica LX1 I tried out produced off color photos.

I am wondering about long term support from K-M regardless of what they say about focusing on digital cameras in the future. After all, they did pull out of Canada rather suddenly. I've heard the A200 is contender from a respected souce or two, but haven't used one.

Do check out the pro review of the G6 here at PR and the reviews section generally.

Hope this is some help?