I ran openwrt and then lede on a wrt1900ac v2 for about 1.5 years until last week. Initially, stability was spotty, but the latest Lede images worked generally well. However, while vlans with Lede worked perfectly with my two TP-Link WDR3600s, the Lede ultimately had issues with it. I tried one last thing, probably bricked it, and that was the last straw...ordered three Unifi aps and couldn't be happier.

OpenWRT/LEDE is great assuming your device is well-supported and well-tested. Unfortunately, the wrt1900ac line was never as open as Linksys claimed it was, the LEDE devs didn't get the support they needed from Linksys when they needed it, and so certain things still don't seem to work.