i always play switch, but i played set when i recently played my japanese sapphire since i mean. i couldn't read it anyway. it was surprisingly fun tbh. and it added to the challenge of the playthrough. i might try it on english copies now tbh. lol i'm always rattataing about the series getting too easy and well. this is one way to help with that.
I've tried playing on set a couple of times, but more often than not I'm just too lazy to change it from switch. I try playing with a self-imposed set rule anyway, but it's not always convenient when training multiple Pokemon.
Set is significantly more fun to me than Switch. It adds an extra layer of difficulty not knowing what Pokemon my opponent is going to send out next. Honestly, I'm so used to the Set option by now that I feel like having a sneak peek at the next Pokemon is kind of... cheating in a way. x.x
I used to switch but then I'd switch and now I'm all set to set.
...Yeah sounds lame when I read it aloud but that's the thing, it's literally exactly what always happens. I play up to about the second or third gym on switch and then that kind of bores me out (more because of the extra slowness than anything else) and I switch to set. Except for the few beginning fights and maybe the E4 challenges, I nowadays stick on set.