Yep, been fine for me. And anyone with a long enough memory will recall I was a consistent and vocal complainer about the rapidly waning v700 support in the X series, to the point of tedium, I'm sure. I did then and still do feel essentially ripped off. But hey, no point raking over all that again.
But if there was a big problem with Platinum, trust me, I'd be the man to spot it.
As far as I can tell so far (two long working days on Platinum), it's exactly the same as it was in X3. Certainly not restricted to Mackie Mode, so I think you have a setup issue.
I'd like support to be better. X1 was worse than 8.5, X2 onwards eventually better than X1, but it's never actually been as good as it was in 8.5 again. Which is fairly shocking I think. But now Roland are out of the picture, and it's been quietly discontinued, I think it's likely all over. I'm just glad they're maintaining compatibility at all at this point.