My vote goes for the Sony DWZ-B30GB. All the advantages of the StageClix but in a nicer package.The transmitter unit in particular is a really good hard wearing piece of kit. I can't fault it - no compounder, excellent range and low latency figures for a digital device. Love the fact that you can shove another pair of batteries in it - StageClix doesn't let you do this, a bit of a let down if you forget to charge your device before the gig. AAs are easily sourced. Even the reciever can work off a 9v battery should you forget/damage/not have enough sockets. Low battery indicator is also on the unit so you don't get caught out. Wide and narrow RF connections means that you have plenty of availble channels for connection should you ever witness interference.
A really well thought out piece of kit. And it's Sony. You know it's good. No drop outs experienced, I've taken it as far as 50m from the stage and it's still good - although latency (that of physical distance away from the sound source as opposed to that introduced by the wireless itself) means playing with a band is pretty hard unless you are using in ears... I also like the connectivity options - tuner out, main out, xlr out... and unique to this unit is the mic/instrument switch and attenuation switch - you can use this device as a lavier mic system and the attenuator switch is really useful if you have super hot output basses.
To be honest, these units are so good, you can't really go wrong. If you get the Line6, Stageclix or the Sony, they will all serve your purpose. Go for the one that you like the look of best.