Rusty Box- How do you use yours?

[Iheartreverb]

I’ve got a Rusty Box on the way as I couldn’t pass it up. I’m interested in whether people use these as an always on preamp or a drive pedal? 
in the case of the former, are you going into an effects return or similar? Essentially making that the sound of your amp.

If you’re using as a drive pedal, how do you find it? 
 

cheers