I've yet to play the game on PC. I'll try it here soon, but I've been enjoying it on mobile.
Every now and then I'll play on the phone but play like 99.9% of meaningful games on the iPad mini.
Personally, I think that the iPad Mini is absolutely the best format for playing. It's got a large enough screen to take advantage of the beautiful graphics but it's not too large to carry around or lap. The detail allows you to be precise (i.e. when putting) to cm's. I imagine the PC is the same if not more precise.
I'm using an iPhone 8 to play rarely when playing on a smartphone.
It's a different game between iPad and iPhone. It is, in many ways, dumbed down for the phone. It's easier to play on the phone and the forgiveness tangibles are much more applied. I can ding the meter about 3 out of 5 times on the phone and less than half the time on the iPad.
WGT has done a good job of keeping it playable and enjoyable on very small formats like the iPhone. I just can't bring myself to only play on phone because it strains my eyes to see the screen.
In short, on the phone, it feels like each nudge of the shot aim point is approx. 1 foot increments. On the iPad, it feels like each nudge is approx. 1 inch increments by contrasts (depending if putting or from distance). So, for that matter, the phone's forgiveness and accuracy is far more dumbed down and usually works in favor of the player.
I've never spoken to anyone who uses a tablet (particularly an iPad) except for one guy who said he was using a Kindle.