I’ve only had it for like 2-3 months but so far it’s done well. I will say that I’ve used it mostly at the beach and in windy conditions (which means the possibility of sand getting into it, dealing with salt water spray, etc.) with no issues at all.
On the lens performance, I’ve been pleasantly surprised. It does focus breathe a little at 300 and not ALL shots are in focus when I’m shooting birds in continuous high (a6300 at 11fps), but it has still exceeded my expectations.