if you must have the machine for live use ASAP Mk1 is obviously a better choice with a more reliable OS that’s being used by far more users for that very purpose
I will probably get a Mk2 at some point, the more durable / higher quality components for the step keys and encoders are very enticing.
Some of my step sequencer keys need to be replaced on my Mk1 OT, and my level encoder jumps values sometimes but I wouldn’t mind making my Mk1 a dedicated 4 input FX box with the Mk2 doing everything else. I’m sure some fun could be had sending 8 midi tracks to eachother as well