I'm very impressed by them. I seem to have a few from a batch that are a bit dicky (they wont accept an address). But otherwise they are (relatively) tiny, very powerful, very quiet, and include frog polarity switching, and two additional switches as standard (for if I ever get around to adding signals!). Best of all, the motor incorporates a decoder, so its' literally two wires to the motor and you are done! I'd definitely recommend them.