It kind of depends what im using that day, pedal/gearwise..
I typically like it after my pedals before my D.I, but Ive had good results BEFORE my whole chain as well..
I like it before anything that's envelope/dynamically responsive- REALLY makes my Digi Bass Synth Wah behave a little more usably, and I've had some success with making my fuzzes less overwhelming by putting it before them.
If I am just using, say, an eq and D.I., I would put it last.
With most compressors, I would use it Before the compressor; it REALLY makes the threshold easier to use and more consistent throughout various volumes and dynamics.
As I said, I tend to just put it last, but I am finding I like it before 'responsive' pedals a lot
The loop-box has seen more active use at home, where it is hard for me to TRULY analyze much of my gear at such low volumes. I tried to use it to move around the Thumpinator live, but it caused a lot of eq/level issues to move around something so dramatic.