I know my own opinion can't be neutral, but I have to write it here: it really works, is cheap, and easy to assembly. Thank to it, I'm rid of parallel/serial ports and MSDOS for the equivalent of US$25 per motor. And I didn't have to weld PICs nor burn EPROMs. And the software is free, open source and public domain. No more I lose 30 minutes or more trying to find a 16th magnitude comet or asteroid in the sky! Using latest version of Soundstepper, even with my "threaded rod/arm" mount, now I can do "sync" in a nearby star, and "go-to" for an object that would be almost impossible to find otherwise.