As an OpenBSD lover and frequent user I will tell you it does not support but a significant fraction of the hardware Linux does, and has many features that are reduced in functionality or just gone compared to Linux.
Is it bulletproof? Definitely! But you need the genius of Albert Einstein as well as the patience of Mother Theresa to actually use it in production.
Can't have a bug in a feature you never implemented and can't have another arising from unexpected interaction of two features you didn't implement.
It's the one security practice that actuuuualy works
For most server setups OpenBSD's hardware support is adequate, and this is especially true for VMs. It's laptops, peripherals, and bleeding edge, high-performance or specialized devices where driver support is a PITA. But that's not something I've encountered running my own private servers. It would be nice to have something like ZFS, but mostly that's a peace of mind and convenience thing--would be nice to be able to stream backups somewhere rather than push around dumps and tarballs, though I have a script for that.