Picked this up last night and just spent about 2 hours messing with it. I noticed pretty much right off the bat that despite Line 6's claims and the hundreds of positive reviews out there that is does affect the tone. Now don't get me wrong, I'm really not expecting a system to give me an absolute 100% match in sound, just enough that I can't personally hear it. You all might laugh at me here but I've owned Nady wireless systems (VHF) twice in my life and I've always personally never heard a difference in tone, seemed seemless to me. The biggest problem with Nady for me is the total shit build quality. My last transmitter cable started cutting in and out and I was super delicate with it and only used it a few times. It had been sitting nicely next to the receiver for a few months before I plugged it in again, no bending of the cable or anything, it just broke on it's own! So I decided to give the Relay a try since it uses standard cables. The first thing I noticed that irked me was the shitty quality battery door cover, I mean really?? They couldn't do better than this?? It's a super thin little latch and with the batteries in you can see them pushing out the door slightly, it actually pushes the door out a pinch. Wonder how long it will take for that little thin plastic clip to snap off or just stop latching. I can't believe they didn't do better than this for the battery door. The belt clip however is nice and it's metal. Playing I couldn't discern any noticeable latency (nor with my Nady), but something just stood out and for a few minutes I was trying to pinpoint it. I tried all the "Cable tone" settings and swapped back and forth between the cable and wireless and then it hit me... it's squashing the low end! Palm mutes just don't have that same oomph and feeling in the chest with the Relay. Even open power chords just don't have as much of that low end growl you feel in your body when standing near your amp. I even checked this with clean chords and found the same. Maybe it only does this with EMG's, as I didn't bother to test my Schecter with passive's cause I need it for both. I don't know but I can see some people missing this because it's a bit subtle but for me stood out like crazy. Outside of the low end it keeps the tone accurate but I also noticed what seems like some very slight artifacting when playing faster runs that I don't get with the cable... it just has moments where it sounds slightly noiser than it should. Anyhow, I'm rather disappointed with this as these models get the best across the board reviews I've personally ever seen on a wireless system. No, my system is not broken, it functions fine and I do feel this is an issue in the design. It's also not the cables I'm using. As I said, the unit functions perfectly in every other way and to the greater majority if ears out there I don't think most would even notice, especially excited kids that write glowing reviews after 10 minutes of use cause they're sooo excited. So this unit is being returned. Even if the low end were reproduced fine I think that weak battery door latch would eventually bite me in the ass as I'm rather sure it would fail over time. We're not playing live yet so I'm just using this in house to avoid stepping (or having others step on) on my cables so I think I'm gonna see if I can just get a new Nady transmitter for now. PS. If this write up disagrees with you and your experience with the unit I apologize. I'm not saying everyone that has positive words on this unit is wrong, not at all. It's just that I hear the difference and am not willing to deal with that difference. Rev.