Mark,
No experience with a PA 3X and...
I'm sure you'll hear from those older and wiser than me...

That said.
I'm now using a PA 4X. I also have a Yamaha Tyros 4(going on sale)and S970. The styles on the PA 4X are not as wide and deep as my Yammies...especially traditional/folk.
However, I've been able to adapt PA 4X styles(for the most part) to my needs. I play two to three times a week(or more) for seniors. I very much like the 4X styles...very alive and the seniors I play for also seem to like it.
Also I really like the 4X interface and controls for live play...more so than my Yammies. If all goes well, I'll sell both Yammies and settle on the 4X.