My main dislike is the colour output. Presumably limited by the SMD choice, the Red is a little orangey, and the blue is far too cyan (making a deep blue impossible to achieve) but really, for the price, one cannot complain.
Brightness is hard to decide upon. When these are facing the crowd, or uplighting a close piece of set, the output is really rather bright. However if above a dancefloor, as many strobes get used, very little of the output seems to make it to the crowd (ie distance illumination is poor) At the power of the units, and the light angle, I guess that makes sense, but I was a little disappointed by that.
As an on stage fixture pointing at the crowd though, I cannot get enough of them. Worked perfectly for my purchase use (tour of a synth pop band who's remit was neon). However these are NOT an alternative to something like a SGM Q5/Q7. But if you like what they do, they are pretty darn impressive.