Does exactly what it's designed for, haven't noticed any perceptible lag or delays, even when going through a digitech whammy,
No way to change the batteries though when they eventually fail, like all other wireless systems of this type
The plastic feels a little on the cheaper side, but I'm sure that's done on purpose to keep the weight down so there's no strain on the instrument input jack, no matter what angle it's plugged in at.
Haven't tried it in a multiple wireless system yet to see if there's interference with others on the same frequency, but since the devices are uniquely paired at manufacturing level, I'd imagine it wouldn't be a concern.