I back the RC3, although mine mysteriously died out of the blue. I did entire sets with it as a backing band, hah.
Anyway, regarding loopers, buzzing and whatnot, I jammed with a friend last night who plays drone gigs with his guitar and a pedal board. He uses a Boomerang, a Boss Giga Delay, a Strymon El Capistan, a Meris Mercury 7 and some other pedals, including distortion and whatnot. His pedals don't buzz at all, and the reason is his Cioks power supply, which is amazing. But he told me he used to have issues before he got it (especially when he also had a Strymon Time-line), which ultimately led to a necessary upgrade.
Buzzing and digital noise can be caused by "bad" power supplies meaning that if you don't use isolated power supplies, there's bound to be some unwanted noise appearing somewhere, it can be caused by mixing analog and digital pedals in the same chain, by poorly made pedals (and TC Electronics being Behringer now...), by long cables or wires picking unwanted frequencies (it also happens in homemade pedals if you don't shorten you cables enough when you do your wiring, hence the advice to the DIYers of always wiring the circuit in the box), etc. I have the same issue in my eurorack when I put some digital modules next to sensitive analog ones, which used to make some modules impossible to use do to the constant buzz. It changed when I upgraded my PSU.
Unwanted noise is most certainly a major headache.
Regarding degrading loops/delays, the Strymon Volante and El Capistan are amazing for that...
