I can't comment directly on the BTR 6 0 PBs but I did/ do have some Skytrex 20mm from the late 'eighties early '90s. They are all completely metal kits, heavy beats. Fairly well detailed, my T-54 holds up well against its plastic chums. Not sure what the moulds are like 20 + years later but when they came out they required minimal clean up, usually just a few mould lines here and there and the occasional distortion or gunge in tracks. The best items were IMO the tanks, which tended to be two or three part kits. I had their M113 which was a multipart kit and it was a bear to put together, part of the problem being the very weight of the component parts the other being part fit. Ultimately only the turret and tracks survived.
For the BTR-60s there is the PST plastic kit as an alternative. Their kits build very easily and look good. For the BRDM Skytrez is probably your best bet. The only other BRDM-2 I can think of is the ACE short run kit, which, trust me, really is a complete pain to put together. In fact where possible I would avoid ACE kits. Great subject material, accurately sculpted but really require too much time to complete.