Bought a nice long cable from AXE music a few years ago, and so far so good. (3 or 4 years?) Generally I beat the hell outta anything I own so I say these kick ass....
I agree, I have a Nady wireless unit but I think cables sound better. I won't mention how I store my cables as I couldn't stand the resulting abuse, but the buggers have lasted tho'. Some are over 12 years old.
I am not familiar with the wireless systems for guitars. But I am positive, cables will sound clearer, especially if you a using it for recording. (If it's live gig, then noise won't matter).
Before sending it through the air to the receiver, the guitar has to do various modulation schemes(like FM) and in the sampling phase the sound quality will get degraded.