Pm727m, hardened gears, no belts to change, simple manual gear box. The variable speed version gives you much more rpm.
I went with the manual, I just don't "need" any more electronics to possibly repair. I don't run at 1700 rpm often, I don't need the higher rpm working in my usual steels. I have a manual 1236 too, it's just preference and cost.
I really like the manual gear box, no changing belt position for the hi/lo ranges. It's a nice option over the PM25. I run slow often drilling 1" holes, the quick gear changes are nice compared to my belt drive machine. The 727 runs good at low rpm and doesn't struggle at all. Well, at least with a 1" drill bit in 1018.
I have been thankful I did get the pre-installed DRO. My first, should of bought a mill with a dro years and years ago. I'll probably add dro to my 1236 too.