Despite my hatred of all things Sony, I purchased two of their cameras in the last few months: a RX100 for my wife, and a RX1 for myself. the bragging rights of a full-frame sensor with a Zeiss 35mm f/2 prime were too much to resist.

• This thing is built like a tank. It feels very dense.
• The mode, AF and exposure compensation knobs, while not locking, have tight detents and are impossible to knock off their settings by accident.
• The big lens means limited handholds, and the lack of a textured grip means it is quite slippery. I dropped mine on a concrete floor, entailing expensive repairs (it was still functional, but the focus ring was no longer spinning smoothly). A wrist or neck strap is a must-have with the RX1.
• It is not compact by any means, comparable to the Sigma DP2 Merrill in bulk. Due to the lens protrusion, it is less pocketable than my Fuji X100.
• The lens, while excellent in terms of sharpness and vignetting, has very severe barrel distortion. Lightroom can correct for that, but you lose resolution in the process.
• Unfortunately it is merely a Sonnar, not a Planar or better yet a Biogon. I don’t remember the 35mm f/2.8 Sonnar in the Contax T3 having this much distortion, though.
• Autofocus is only so-so.
• Image quality at high ISO values is outstanding, as you would expect from a full-frame sensor from the leading manufacturer today.