If I had the time and patience, maybe, Donny...
Trouble is, just like you, a busy gigging arranger player has little time to sit at home for months to reprogram and create styles before he can even USE the darn thing on a gig for anything more than a VSTi player. Just like you, I am pretty content with the quality of the sounds in my personal choice of arranger for gigging with, and certainly have little complaint at the quality or selection of styles included, or converted styles from other sources. The piano is stellar, the organ is very good, there's little in the soundset that needs improving for live use (I haven't even got any SRX cards yet!), the drums are amazingly live, and the OS makes changing any of it child's play...
And when I DO need VSTi's in the studio, my computer system can already do it. Loops, likewise. And being heavier than my G70 already is, I can't see carrying TWO big heavy keyboards, just to get a few things I don't really need on stage. If the MS soundset and styles blew the G70 away, I'd already have one. But seeing as this is what I primarily need from an arranger, and I can already do everything else in software at the studio, it has nothing I need.
I bet the majority of MS's out there are relegated to being B4 and GIGA piano players and the like, while, if their owners ARE using styles primarily, they are using a different arranger. Simply because pros don't have the TIME to turn them into a great 'arranger'. If a great, well styled and voiced arranger is available (for less money, at that!) of the shelf, who has got time to turn one that isn't into one? I could be programming styles, or I could be gigging. I know which makes me money...