The focus wheel on a handful of vectors(including my own) I've heard personal reports on(friends I know and trust), it has lash in it. Almost like a spring needs preloaded before the focus is adjusted. The depth of field in the vectors is very good, so there's not a lot of focus adjustment going on anyways. The glass IQ is not zeiss, Leica pro, swaro El level. It's better than a lot, but not alpha. The system hasn't given me a target I couldn't range yet. Atop a Tripod, no problem ranging trees or ridges up to 4k yards. Cold weather performance, run cold weather rated Nitecore 18650 batteries, they're rechargeable and through testing, superior to cr123a.