Re Sabertooth I have used one (25A) in featherweight robots and in Pilgrim the big walker (This has two 250W 24V motors to run it, even when I get it to dance the speedo dose not get warm),for a long time and had no problems with it at all. I know a lot of Roboteers that find these speed controllers fine. Most problems seem to occur when you try to run 2 motors off one channel but if you steer clear from that they seem to work fine.