Hi,
I have had an alpha spid az/el rotator for over 12 months now and have found it to be an excellent unit.
It is mechanically very robust and turns my 5 el 2m X yagi and 19 el 70cms X yagi with ease. The Spid will run on AC or DC. After a few months running on my shack 13.8V supply I decided to buy a toroidal transformer with 20V output and make a dedicated PSU for the Spid. This proved to be much better in that the rotation time for a full 360 degrees is now reduced to 61 seconds. The "mouse" control is a very nice extra feature, very handy on the operating desk.
If you go for full computer control for az/el it is fairly easy to set up, I used the tracking program Orbitron.
I can only speak for the UK distributor Braeside Communications, whose service and responsiveness to questions was first class, even getting e-mail responses back quickly at the weekend.
Criticisms - the manual supplied for the UK could have benefited from a few improvements, which I believe are in hand.
Tips - follow the recommendation to allow plenty of cable drop from your antennas. The spid can travel past 360 degrees and could pull the cables out if you don't have enough slack. Keep a note of the pin outs and cable colours back to your shack, just in case you need to do repairs in the future.
73 John G7HIA
ps/ no connection with the companies other than as as satisfied customer.