BHyVe currently has some good sides and some bad sides. The good sides are that it finally (!!!) exists and that apparently it does its job with very high performance. The bad sides are that it is still very experimental, not present in the base source tree, that it requires dedicated memory for VM guests (i.e. the host OS and the guest OS cannot share memory, cannot swap each other out, etc.), that it requires a very recent Intel CPU with nested pages (or EPT), and that it currently only supports FreeBSD guest operating systems. As such, it is very "bare metal." I'm sure more funding for the developers will be appreciated.
One other piece of good news was a consequence of the BHyVe effort: it prompted the development of FreeBSD virtio paravirtualized VM guest drivers for storage and networking, which can be used with other VM hosts.
Unfortunately, all my test machines have older CPUs which do not support EPT so I cannot test it, but the authors and myself are eagarly waiting for comments from other users :)