I use an M2 and MP and love both but the day I held and used a IIIA I was surprised at how much the smaller size and overall feel was so much more comfortable to carry and use as a pocketable camera. Main downside is the more squinty viewfinder but the extra care for me often results in more careful images which is not so bad. I upgraded to a IIIf RD from Youxin last month and love it even more using it with an uncoated 35/3,5 Elmar.