Durn ... you're right about there being a scarcity of information! Looked at Align's website, and most searches led me to pages entirely in Chinese. Did manage to find the manual for the Al-200S, which I would hope would be similar:
http://www.align.com.tw/ManuaLib/powerfeed/G00391A-200S.pdf
Looking at wttool's pages on the two feeds, the only difference I could find was that the the AL-99SP (Meda brand/WT import) claims an RPM range of 0-200. The Align AL-200SX claims an RPM range of 0-165 RPM, with a rapid speed of 240 RPM. Both claim 165 inch lbs of torque. Both pages refer to catalog page 153. Had a difficult time getting there, but no additional info.
A couple of years ago, I bought a used Grizzly mill/drill with an AL-99 on board, but this one was actually made by Align. The motor was shot, and I couldn't get replacement parts for what was now a museum piece. So I cobbled together a drill motor and speed control to drive it. I get the feeling that the motor failure was not the result of a flaw in the drive, but no strong evidence either way. My best guess is that Align sold the AL-99 design to some other branch of China, Inc., then made a few improvements (possibly the electronics) and renamed it AL-200SX. But again, that's just speculation.
PS - among my search results was a vendor of replacement parts for Align table feeds:
http://www.gromax-usa.com/supplies/powerfeed/Most_Common_Replaced_Parts_N.pdf
Note that they list parts for the AL-99, but not the AL-200.
Good luck!