I use the loop in my Mesa/Boogie Electra Dyne. I only run an old Line 6 DL-4 delay. I do get a tiny bit of ground loop hum, but I only notice it when playing at home at loud bedroom volume. I've never taken the time to try to quieten it.
I use the amp's drive, a TS-9 to boost the front for more gain(seldom), and the delay in the loop. The amp also has a glorious spring reverb.
The Electra Dyne is one of the best sounding amps ever, and one of Mesa's most underrated. It was released with the Mark V and with it's single channel aesthetics never stood a chance. It's also quite low gain, especially for a Mesa. It's basically a Fender Twin, a JTM45, and a JCM800 - single channel control layout, with 3 footswitchable modes.
My other rig is a couple of dirt pedals and a simple analog delay into a Fender Deluxe Reverb Reissue. Both rigs sound great: clean, the Deluxe Reverb gets the nod, barely, but overdriven it's the Mesa all the way. Clean amp + dirt pedals just doesn't quite have the mojo or the magic that a great overdriven amp has imo, or maybe I haven't found the right od pedal.
I would love to try the JHS Angry Charlie or the JHS Andy Timmons @ pedal, plus a Charley Brown to use as a low gain od.