I haven't, but I've been casually following its progress. It's been around a while now (introduced in FreeBSD 10.0, with 10.3 and 11.1 currently the stable releases). By all accounts it covers off all the basic things you'd want from a virtualisation system, and supports libvirt so it can be managed by all the standard open source tools. BSD already has its excellent jail system, which should solve any need for BSD-on-BSD. But if you're wanting to virtualise other stuff on BSD and don't have crazy requirements, it seems bhyve is perfectly capable.