My experience is with the Festool CT 22 but I think the Fein would do
the job just as well based on comments made by some Fein users I
know. I have the older Festool 150 (the Rotex) and I've used it in
inverted and angled postions and it got heavy. (4 pounds, I think).
I've had to switch hands often or use two when possible. I use mine
in a log home, sanding the beams, walls, underside of ceilings, etc.
Dust collection was excellent.
I ended up buying the smaller DTS sander for my wife because she did
not like using the Rotex on any surface other than horrizontal. Plus
the delta shape pad allowed me to get into corners that a round pad
One thing I think that makes the Festool preferable to the Fein is the
Festool has a flat rectangular top that provides a good platform to
set your tool, and if you have other Festools, their carrycases
securely mount to the top.
I think you'd also benefit from the larger of the three- the CT22 vs
the Mini or Midi.