I've been using i3 for years, there's just nothing that compares to a tiling window.
If I'm in windows I use virtuawin with alt+1, alt+2, etc for switching desktops. Not nearly the same, but works so much better than the builtin crap Windows has.
Paradoxically, I don't use alt+tab in windows to switch between programs. I used to do that, but then around XP (I think) they added the ability for programs to inject themselves into the alt+tab list. That means it's no longer completely consistent, which means I now have to think and check what alt+tab actually does so it stopped being any faster than just using the mouse.
So now if I need to flip between them quickly I'll either put them on different monitors (I use 3) and/or put them on different desktops. The combination makes me effectively as productive without the use of alt+tab. And it feels similar-ish to i3, so it's a bit comfortable in that respect as well.
NOTE: Anyone thinking virtuawin is like i3, it's not. It's just the best virtual desktop on windows (imo of course). Nothing on windows comes close to i3.
