Indeed, OpenBSD is great at what it does and like Slackware on the Linux side, it isn't for everyone but it certainly is awesome in its own right.

The only technical limitation I've run into as far as using it as a daily driver OS, is that it can be a bit slow even on very fast hardware. It's simply not optimized for desktop use, though it is certainly usable with a few tweaks. It's great for older hardware too, where the speed issue is relative. In fact, I've found it to be a perfect fit for a couple of old laptops in my collection.