I finally got around to trying i3 a few weeks ago and I wish I'd done it a lot sooner. I installed it on my fairly crap dell laptop that can barely run windows 10 (windows in unusable on spinning disks) and it flies, everything is instant, alt+enter and the new terminal is just there, alt+d and the searchable program menu appears (windows could take several seconds to a minute), alt+3 and I'm on different virtual screen. The only time I find myself waiting for anything at all is a new browser window or the funky lock screen installed but I'm pretty sure both of those are solvable.
The interface is fantastic, it's the first WM I've used (apart from maybe tmux or vim) that actually manages my windows well. In hindsight the desktop metaphor is such and obviously dead end that we've wasted for too much time on. It will take some retraining, but even things like tabs in the web browser no longer feel necessary, the WM can handle this and give a consistent global interface. MS is kind of heading in this direction too: https://www.theverge.com/2017/11/28/16709190/microsoft-windo... .
I started off with the manjaro distro (https://manjaro.org/category/community-editions/i3/), it's got a fair bit of bling that you won't get by default elsewhere but the performance is great.