This IEM system is fantastic value for money.
With 16 channels to choose from, for pub/club/function use, that's plenty.
It's easy to hook up the transmitter and receiver and the sound reproduction with the included phones is decent enough for a singer to use, however I would definitely recommend spending some extra cash on a good set of phones. I use Shure SCL3.
Using good phones means you get to appreciate that the system itself has really good sound quality from lows to highs, although (speaking as a bassist) the bass is perhaps a little lacking compared to some of the +£100s more expensive models.
The unit would be better kept in a rack rather than setting up every gig. We've not done that and you tend to notice that there's a price element built into the construction.
All in all though, unless you're going to be playing in situations where the available frequencies will be a limitation, there's no reason why this system plus some quality phones won't be every bit as good as other systems costing loads more.