I believe in one size fits all..

I have used my pair of Roland Keyboard Cube 100's for more than twenty years..

I have never played a job they couldn't handle...Gymnasiums..outdoors...loud rooms ...and quiet settings...

They do weigh 70 lbs each, but are on casters..

My choices are stay in stereo [90% of the time], or take one [mono]..Roland doesn't suffer from the mono thing like Yamaha..

I do keep a small amp[Roland Keyboard amp 60], for a house rehearsal or party and also as a stage monitor[if I need one]..

This is all the sound system I need..

The band [trio] I work with use a Yorkville set up...two 550 watt power speakers and a 600 watt sub woofer...We never exceed 1/3 of the power, and we play BIG venues...
I could easily do the same jobs with the Roland set up...

I would get a system that handles your largest jobs and don't worry about the small jobs[the volume knob turns both ways]..