Granted, I do not have the habit of playing games or using large, unsupported software (say, Photoshop and friends). My daily applications consist of Emacs and Firefox, so my feedback may be limited in scope.
I'm not sure what the status is, but last I checked Electron did not work on FreeBSD. If you use something Electron-based, you might want to take a look at it.
I also am unable to access my iPhone filesystem and to watch Netflix movies. But for both cases, I blame the vendor and not FreeBSD. A VM on bhyve quickly solves the problem.
Guest overhead will vary by workload. I know for example that virtio-net performance lags Linux, because virtio-net was designed for Linux skb's and doesn't align well with FreeBSD's mbufs. Give it a shot and see how it compares, I guess.
While rough around the edges, it can be comfortable enough that I forget about it most of the time.
All the BSDs are better if you're not using the shiniest of hardware, they do eventually get hardware support for things, but not always at day zero.
From a philosophy perspective, OpenBSD seems to prefer sane defaults and a complete base system. For the laptop, I needed to install no packages to get a fully functioning system (minus a web browser; that was the first and only thing I installed). I had to do more “basic” configuration on Free than on Open, but I ended up doing quite a bit on both.
OpenBSD has a somewhat strange update system, where patches to stable packages are not provided, requiring you to either build updated packages yourself, follow —current, or use a third party (M:Tier, for instance).
My recommendation is to try both and see which works better on your hardware and which philosophy makes more sense to you. They’re both great operating systems.
The installation is very quick and then it just work on my t470. Documentation is excellent. Try it.
However my box doesn't feel as snappy as a lean Debian 9 install with xfce4. You have to decide if that's a dealbreaker :)