Hi Chris,
Yes I use them and in my opinion they are the best on the market, I have one of their motor g/boxes waiting to go in my 2251 when I finally get round to it. I use the one they stock that was originally from Ron Chaplin and has helical gearing, so smooth and quiet, also they did and probably still do, give you 10% discount if your a member of the guild.
Martyn.