I've gigged with it. Aside from the display lagging on the Remote and the slightly laggy behaviour of an expression set to wah pedal, it has been stable for my use in that particular band/project. There's another band I play with where the lag wouldn't be acceptable though, so I downgrade to 3.3.0 with them. All I can say is to try it at a rehearsal and see. You can always downgrade again in a break.
I gig with it and have the same issues. Every once in a while the sound guy's head will pop up when I use the Whammy (Morphpedal to Pitch.) Kinda funny to see, but it would be nice to have it fixed. (Yes, I submitted a ticket.)