If you ever remove the frame counter dial, be careful with the counter spring that is in there. It breaks very easily, and then the frame counter will no longer work unless you find another spring. Micro-Tools used to sell this spring - not sure if they still do.
The lens is single coated, so be mindful of where light sources sit.
The Xenon lens is excellent.
The body is a bit small, and with the lens door open, there isn't much room for your right hand to grasp the camera. This is always an issue with lens doors that open side to side rather than top to bottom. All Retinas open side to side.
The Retina IIa lever wind (there was a Retina IIa knob wind) is among the most popular of the Retinas and considered by many to be the last of the true folding Retinas. Personally, I find them all very interesting.