I am one of the "Effects Loop or Nothing" guys. I have tried this pedal numerous times in front of amps and never noticed much of a difference. It probably did what it is supposed to but I never noticed much.

Few days ago I played a guy's rig that had his in the effects loop and it was literally night and day when you clicked the thing on and off. I bought it the next day and it sounds great in my rig.

I like the lo conture at 1 o'Clock but I've been in a constant battle with the process nob. I love it all the way up for leads but for everything else I have to compromise and keep it around 3 o'clock. Worth giving it a try on your own rig for sure!

BUT: For Live, the louder I crank the amp, the lower I have to set the process. At higher volumes the process begins to literally slice people's heads off because it really increases the presence. When I play at stage volume I keep the process is no higher than 10 o'clock.

Oh one last thing to note, I noticed that with cheaper guitars the pedal made an even bigger difference. It seemed to really make lesser quality gear shine making it even more worth it in a low quality rig.