I was lucky enough to see Primus supporting Rush on the Presto tour in Glasgow in 92. Les was outrageous, playing his Carl Thompson six string fretless Rainbow bass throughout.
 
I recall that Primus were much louder than Rush that evening; it kind of reduced Rush's impact once they took the stage.

This was a great show.  No opener.  They came out, played with nary a five-second pause between songs.  No banter.  But, holy cow, those guys have some serious chops.  Several Carl Thompson basses made appearances, including the infamous Rainbow Bass.  Great bass sound during the show...sort of like a rooting hog (Note:  strange as that sounds, as an Arkansan, I find that sound appealing).  The highlight was, for me, a toss-up between Fish On and Renegade.  Highly recommended.

Now you've done it:
 
Now Mica is gonna get swamped with calls regarding what wood recipe you use to get that 'rooting hog' tone . . . . .
 
J o e y

I had a chance to meet Les and J Lane in a music store, a couple months back.  I just didn't have the nerve.  Les is really tall!