Another happy X100 user here, I haven't touched my Pentax gear since receiving it a few months ago and am thinking of selling most of my Pentax gear except the body and macro/tele lenses
Greatest pros:
-viewfinder (both the evf and ovf)
-JPG quality
- built in film and B&W filter modes
- build quality, manual controls
- high flash sync speed and great ttl when using the onboard flash as a fill flash (which you can do in broad daylight!)
- built in ND filter
- silent
biggest cons:
- manual focus is horrible even with the newest firmware and especially if you are used to Pentax limited lenses
the ring is as smooth as a limited's but it just doesn't do anything!
- the minimum focus distance for macro mode is too large.
- in AF mode the camera often focuses on the background instead of the subject with close subjects, especially when using the optical viewfinder. This is a major drawback as you can't just hand the camera to someone who never used it without setting it to electronic viewfinder and macro mode.
- auto iso switching is a pain to change, there should have been a dedicated iso button
- Hood and adapter needed to mount filters do not come included with the standard model. Cheap third party alternatives are available.