I'm a big fan of the Shuttle. I have a 6.0 that I bought used on talkbass. Any bass with a decent amount of output can overdrive it if you push the input (the only bass I have that doesn't get much grit out of it is my Danelectro). I also really like the tone controls on the shuttle - simple but effective and it always sounds good to me. I've gone through Peavey, Randall, GK, Eden, Thunderfunk, and AI heads and this is my favorite amp I've ever owned.
I run mine into one or both of an EA CXL112L and CXL110. It is a ridiculously loud rig for the size.
For comparison... At our practice studio, the bass rig has a fancy Aguilar preamp on top of a hefty 1200-watt power amp (I forget the brand).
I usually bring the shuttle and unplug the rack rig
We've got two quite loud guitarists and I have no problem keeping up.