What's your experience with BSD on the desktop?
OpenBSD was created and continues to focus upon security. It's not meant as a desktop. Well, not in the sense of desktop as you know it.
If you do almost eveything from the command line, then you'll be OK with it... which I would bet a ton of money that you don't; you want a GUI.
Oh, I'm sure there is a way to install a desktop using the package manager, but I do not know if the X server needs to also be tweaked beforehand. This is something that you need to research. There's OpenBSD documentation or you can join a hard-core OpenBSD community to sort it out.