Playing my 5 string active/passive bass with Sennheiser XSW-D Instrument Base Set over 1.5 years, at least once a week 2 hours rehearsals in a studio or at home, had 4 gigs about 1.5 hours, compared with a cable when recording.
Stick a sender directly on a guitar and jumping on a stage with it, never lost.
Pros: Not a single drop, ever. I don't hear or feel a difference from the cable, lows are deep lows, highs as crisp, level (gain) is the same, passive or active. Ability to mute/unmute.
Questionable: battery life could be lower than advertised, your mile may vary, but I'd not rely on it for over 2 hours.
Cons: cable included is too short to use with a belt clip on a belt, I discarded this option as unreliable. Receiver jack is moving freely and doesn't keep the angle, which is not a huge deal.