I've tried a few times going the modeler route. I play weekly at a church venue.
Traditionally I have always used a guitar > pedalboard > small/med amp > SM57 mic > Into a GLD-80 digital mixer
I mainly use single coil pickup telecasters.
There are lights on a dimmer but supposedly on a different circuit. I believe they are halogen bulbs.
I do get a little bit of noise while not playing on a normal basis with my amp setup but it is completely covered up while playing so its a non issue.
The issue I do have is that with the Kemper or the Amplifire modeler, is I always have a louder buzz that sits behind my notes. Its especially evident on single sustained notes.
The problem is slightly better with the lights off but its still there. I tried both the XLR to the PA and also the direct out to a JDI direct box. It happens with both.
The buzz is only there while I play and with the guitar volume off there is no noise. I'm puzzled why I have a bigger noise issue going direct in as opposed to a normal mic'd amp. Its noticeably different and a complete deal breaker until I find a remedy. I have no issues at all at home with the Kemper and its not an issue of the device. The tones sound great through the PA but the buzz is bad. I also tried the ground lift, no change. I do have a humbucker guitar I am going to try but I really prefer to use my telecasters.
I love the Kemper and really want to use it live!!!