You can tweak those Yamaha stereo samples to sound better in a mono situation.
How can you trash the benefits of SO many other advantages to accomodate the one or two weak links in Yamaha's sound banks?
Here's how I see it:
Voice - better in PAS
Bass - Better in PAS
Drums - Better in PAS
Piano - Slightly better in stereo

That's my order of importance too, so if the weakest link is the piano sound - then fix it! I did, and I love the result.

Adding a second tower for stereo is not a "fix all" solution. The way this unit spreads the sound is so different from anything else you know. It's almost as if a second one is a waste. I use two, 2 nights a week....and I've gone to using them in dual mono because the stereo separations is not as pronounced as it is in a system that is more directional. These poles are SO efficient ..... you really just have to find the sweet spot and then enjoy the ride.

Naturally, if you don't set it up to sound the best ... then it won't. You can't just plug in and expect it to behave like your Mother's old PA. It's a new desigh and it works differently than all the rest. ALL the rest.

Believe me - as fickle as I am with gear - I'd dump these in a heartbeat if I thought that anyone made a better sound system for me, but so far in EVERY catagory, the PAS has proven to be a clear winner to reproduce my sound for my clients.

The weakness is in the Yamaha samples .... not the sound system.