Yes, I had 2 CQB-2s with Blade-Tech OEM sheaths and I've never seen better production sheaths - substantial kydex slabs, not any larger than they needed to be, good fit all around the blade, especially where it met the handle, and set up for a mini Tek-Lok (sorry, can't find a photo of the CQB2 in sheath).
My thoughts on Kydex:
-a secure fit is the highest priority
-as long as it doesn't compromise the security of the fit, ease of getting the knife back into the sheath is nice (but don't make the fit sloppy just to make it easy to sheath the knife!)
-keep the size of the sheath down to a minimum; foldovers can be more compact that 2-pieces (and I think they look better), and that's what I like on small fixed blades, where rivets on both sides just make the sheath wider than it has to be
-the retention system has to match the fit; if it's a secure fit like it out to be, then you have to have some kind of hook at the end of the belt clip to positively hold the rig in place during a draw (I've had custom knives that had nice snug sheaths, but the belt clip just used friction to stay on your pants - it looked nicer than most J-clips, but wasn't secure enough); make the belt clip removeable so the buyer can substitute a Tek-Lok or something else if they want to
-if you're not going to provide industry-standard Tek-Loks with the sheath, at least put the rivet holes where they match a Tek-Lok and make them big enough for the screws to go through (but Tek-Loks do give the user a choice of knife orientations which is a selling point for some peoiple)
Once someone handles a few fixed blades, they come to realize that the sheath is just as important as the knife. I have sold or traded away several excellent knives because the sheath wasn't up to the same standards, and now I won't buy a fixed blade without deciding that the sheath is going to work for me. In fact, I think it's a lot easier to find an excellent knife than an excellent Kydex sheath.