I'm surprised that the analog works pretty well. It's not perfect, but the Joycon analog has less travel distance and is "tighter" than the Pro Controller analog, so that makes it's a bit easier to play.
I even played table top mode with the Joycons in horizontal grip, and it takes a second to get used to, but after that I was pulling off combos with no fuss. Just make sure you got that wrist strap though for the L/R buttons. I still would like a Joycon with a D-Pad on it though, but surprisingly SF2 isn't bad with the Switch's analog stick.
I think it would be more of an issue if someone like Guile is your main rather than a Ryu/Ken, because the analog movements make pulling Hadokens and Shoryukens easier in some ways.







