I have like, three window managers installed on my main machine running FreeBSD 13.0-R
I'll describe my brief experiences on those below.

cwm
Hardly know anything about it, aside from it being built-in on a OpenBSD base install. 
Turns out it's actually pretty good, and well documented. Configuration file is also quite simple. 
I'm just too lazy to get myself used to it.

dwm
A window manager I once disliked alongside i3 for no reason at all, besides from extreme shilling from some of its users. 
Only issue I had with it was because of conflicts with profanity and weechat, so I ended up recompiling it from the FreeBSD Ports tree and it uses the Win key instead of Alt. 
It became my second-favorite window manager, and I use it as vanilla as possible, mainly to avoid it turning it to shit.

i3
At first, just like with dwm I got very weirded out because I came from using w9wm, its perfect opposite. 
Adapted myself quite quickly to it over time, and eventually became second nature to me. 
It's pretty smooth from my experience. 
At least I was looking to make more use of my keyboard, and I guess I've already achieved that with tiling window managers.