they seem to be pretty good as far repeatabiity[my buddy has one]the only thing i dont like about burris knob system is the fixture below the knob that shows your corrections or zero can pop loose[easy enough to fix though].the other is the fact that when you change power settings the whole eyepiece moves,it works fine just seems weird to me.my-2-dave
6brguy, they've redesigned the BD scopes to eliminate that annoying feature whereby the whole ocular assembly rotated instead of just the typical magnfication ring.
The new BD also features a side parallax adjustment knob, at a slight price increase as you might expect.
Also, the Pentax LS30 (lightseeker w/30mm tube) is virtually the same as a BD (made by Burris in CO for Pentax), and featured the regular mag ring and a smoother transition from the maintube to the objective (unlike the kinda blocky looking older BD version).
Some of the LS30 scopes were on a real good closeout a few mos back via Bear Basin if I recall.