Check out this lengthy discussion on r/BSD when a Linux user asked which BSD distro they should go with. The top comment has been quoted.
I am in a similar situation.
All these tests have been made on a ThinkPad T400.
I’ve been using OpenBSD as a server OS, but after trying it on the “desktop” I chose to not use it. I find it to be too slow for my tastes.
NetBSD and FreeBSD are both okay as desktop OSes. NetBSD is fine, runs fast and cool, but Xorg is still a little bit too slow for my tastes. Their port/binary system is awesome, has a lot of software ready to be used. Everything worked out of the box, the only issue I had was a general sense of slowness.
FreeBSD is totally another story. It’s as fast as Linux on this hardware, has a lot of software ready to be used and the hardware support is again, not an issue on my hardware. The Linux compatibility layer works OK too, for example Telegram Desktop is available on the official repository and runs through it. CPU power saving works, just like suspension.
If I had to use a BSD operating system on a desktop computer, I would go for FreeBSD.