Chuck,

If you're doing a tri-gear setup, DEFINITELY go for pneumatics. They are so much easier to set up, plus all you need is a single mini servo to control the valve instead of 1 or 2 big retract servos.

I like SpringAirs because if you lose pressure in the system they automatically come down. No more gear-up landings! Of course, with SAs you have to deal with transporting the plane with the gear down, although somebody on here a while back had a clip of some sort to hold the gear up while transporting.

Tim

PS - the Aurora maidens on Sunday!