I have MS400 and it sounds good. 15 is better but a little heavier. The only thing I notice on my MS400 is when I use the 1/4 input my keyboard sound low. But the XLR is louder. What I did is just use a small mixer and use the XLR input. The Mackies looks cool on the stage though. I like that blue LED indicator. But for me Yamaha sounds good with its (15) speaker. I paid $599 when it first came out. I hope it has a wheel caster just like Samson's