I ended up picking up the Switch version last night while browsing the eShop out of sadness that I couldn't play the Tetris Effect demo anymore.
It's not as polished or as pleasing to the eyes and ears as the PS4 version (which I imported long ago, so I am not double dipping on that one), but it is still really good. The default track list is bigger than I expected it to be and there are a lot of good picks. The anime and pop sections share a little too much with the PS4 game which hurts the value for me, but the return of the minigames makes up for that in a big way. I was happy to know that mini games were making a come back - I did NOT, however, expect there to be so many! The PS2 era taiko games would have 2-4 minigames each if they had any at all. This one has at least 10 out of the gate and lots of slots for unlocks to come later.
I am playing with a pro controller for now but considering importing a drum. I did NOT try the motion controls yet as I have a wrist injury right now that has rendered my right hand pretty much stationary for now. Compared to the DS4 the Pro Controller is not ideal for playing taiko - the left stick is too close to the d-pad and I bump it all the time. Still able to clear Extremes up to a 6 on it so it's not horrible, but it definitely comes as an annoyance.
I need more time with the game to really judge it, but I would say right now that if you don't care about the minigames and just want the best track list and the best quality taiko game to date, get the PS4 one. If you like the minigames and want that portability, then the switch version is still a great step up from the old Vita version, but after playing so many hours of the PS4 version you'll notice the drop in quality when it comes to the engine.