Thank you all for your input, it helps me a lot.
The high quality abilities of the M200 end if you want to print a flat large part (e.g. a front panel for a device enclosure) that has holes for switches, jacks and the like.
Examples of this are in my bugtracker record about disturbed surfaces. I had better results with the UM2 (too much trouble with that printer in all other aspects) and best results with the Pharao ED (finally too small build area).
Actually it's not the fault of the M200, it's the inability of the software (developers). If one prints the part without the holes it's a smooth surface, otherwise not.
Build room would fit with the Form 2, but the cons you listed, especially that there is warping too and material that gets brittle are show stoppers.
Maybe I have to wait for the UP Box V2 (the ones I had have been a disaster regarding manufacturing quality) or take a look at the german reprap 350 (heated chamber like the UPB).
Up to now the M200 ist the one with smallest compromises to accept, but finally it does not do what I want it to do.
BTW, printing the front panel upright results in a smoother surface (because it's a vertical wall then), but the infill shows up thru the surface (because you cannot define more outer layers) and that's another kind of disturbance also (no I don't want print it in black :ph34r: ).
To be clear about that, I'm talking about boxes with 200x120x80mm volume originally, sized down to about 17x12x80mm meanwhile much rounder but with same volume after all.