I've got the Line 6 Relay G50 and its pretty good, no tone change and no issues with the actual device. Its never failed to work, its never given me drop outs and no interference from radio/ambulance, etc cos its digital. I've had it for 2 years.
If I have one criticism its the transmitter not being very secure with the clip but nothing a good round of gaffer tape can't fix.
Now I can't see myself going back to using cables, I move around a bit on bigger stages and its a lot neater without trailing cables all over it. The only times I have to go back to my board is to tune or switch channels, so I'm free to roam around!
When I bought it was £330 or something but now they've lowered to £240 which I know is out of your price range but its worth paying a bit more, to me I wouldn't want to get a cheap AKG wireless for £89 or something cos I've heard stories they cut out and stuff. The G30 must be around £117 now they've lowered the prices. I only got the G50 cos its got a metal transmitter casing (instead of a plastic one) and you have more channels on the receiver. So if I wanted to do multiple guitar changes I simple have different transmitters on different channels. Also the G50 gives me 200ft of virtual transmission range whereas the G30 only 100ft. I'm probably never going to grace big arenas but nice to have that comfort and freedom!!