I ran 12s for a very long time, last rig with a pair of GK neo 212s. Can confirm a single 212 will be sufficient for a one cab solution. When I jumped to Mesa I went with the 215. My reasoning was not tone, it was the 215 will move a smidge more air than the 212 "just in case".
Do not regret that move, and would also point out the 215 has built in tilt back casters and handle that make it super easy to move. You wont go wrong either way though.
The 215 is great. A plus is folks always think I’m working way harder than I am lugging it around. I’ll be lifting the cab on or off the stage before or after a gig and folks will run up and say, “oh my gosh, let us help you!”. I just say nah, I got it and easily move it around. They think I’m Superman.