I was sceptical at first to buy this, because I was surprised by how much less it costs than most of the wireless units. However, as my first wireless system it was well worth the purchase.
I've been playing it for a week, and it sounds great. Definitely clear and crispy sound, doesn't seem that any frequency is cut out. The range is great, too: first thing that I did when I tested it was plug it in, hit record and walk around the flat. It only audibly cut out only once for a split second, and that was when I was ~20m away behind 2 solid walls. When I was behind one wall you could hear some hiss, but only when wearing headphones - didn't hear it on speakers. The transmitters connect to the receiver instantly: when you flick the switch, it's connected. The fact that the transmitters run on battery is also good and bad - means you can swap them out any time, but you might forget, as there is no battery indicator.
Of course, the build quality can be better, but I can't say it's "bad" in any way. The on switches can get stuck in places, and the transmitters are made out of plastic - but if you're careful, it shouldn't be a problem. There is some hiss when operating, of course - you can hear it very slightly when you pluck a note on clean setting and listen - but it's barely audible. The cable is a bit too long, but also manageable. A problem that I can see is that it's operating only on 2 frequencies that you can't switch - meaning if you play gigs at places with other wireless gear, you're going to have to check beforehand that there is no interference.
If you bought this and are getting bad sound - don't forget to play with the volume, as both the receiver and the transmitters have volume controls - which can be nice if you have hot pickups.
I found myself forgetting that I'm playing wireless when practicing - which is a good thing, since it means that the unit operates seamlessly for me. All in all, great gear for an even better price.