1) Fan noise: I've been running my m200 for 10 hrs a day since April with no issues.
2) No problems with the digitizer.
3) Screen: good. not great. I've heard the new motion has an awesome screen.
4) Ruggedness: I keep my m200 in a backpack. I have not been too rough with it but have had no issues with it.
Good luck on your decision.