I put the SW on one of my scopes and to answer the specific question:
Yes these things help you achieve better focus for astrophotography
Not necessarily precise focusing as they do seem to use stepper motors so if precise lies at 1/3 step you wont reach it, thats not to say you'll be out of focus and you'll be far far better focused than you can get by hand on most scopes, especially if they have only their standard focuser.
The SW unit is dead easy to install and i only used it with its handset and was happy with that. Biggest problem is seeing. I would get focus and the seeing would change ,chase focus again and it changes again. Took me a while to just get focus and leave it knowing the seeing will probably come back. Fiddling on the fly only ruined my capture sets
