Yamaha EMX 312SC powered mixer with Yamaha S115IV cabinets.
I've seen guys with great systems that sounded like crap and guys with lesser systems that sounded good. I believe that a large part of how a system sounds is based on
HOW MUCH EFFORT THE HOST PUTS INTO MAKING IT SOUND GOOD. With a good EQ setup and a little time and effort any decent pro PA system that works (with nothing blown of course) can be made to sound good.
If you buy the best gear you can afford (regardless of the brand) and take the time every night to make sure it is EQ'd correctly for the room you are in, you will always have a great sounding show. Even if I'm in the same room for more than one night, I check the front sound every night. Things like weather and how many bodies are in the room can make a difference.
Also the less the gear weighs, the better.
THIS IS JUST IN MY OPINION!
Jim