Re SB quality control and worm tests in house, for ME anyways:
http://www.bisque.com/tom/PEC/pec.asp
"Great pains are put into both cutting the gears and worms (done in-house) and then accurately mounting them!
NOTE! ALL Paramount MEs' are run-in BEFORE shipping and the periodic error is measured in-house! The Paramount ME is guaranteed to have 5 +-2 arcseconds or less of periodic error BEFORE training the error. After the correction one can expect 1 arc second of error or less when using PrecisionPEC to train the error."