It's funny; every single combo amp mentioned in this thread is killer. Think about that. The market focus for bass amps has shifted to the point that cutting edge innovation is now focused primarily in what was once a throwaway demographic: portable combo bass amps. I daresay because of that, the sound of most of those is superior to many of their "upmarket" bigger cousins.
The determining factor between them is now reduced to tonal nuance, not simple reliability or functionality. It wasn't so long ago that bass combos came in two basic flavors: the workman models like the Peavey TNT series or the pricey boutiques pioneered by amps like the SWR Redhead. Every amp company made some model of combo, and they were probably their biggest sellers, but their innovation focus and advertising was on their big-stage rigs; not so anymore.
That's OK. It leaves more SVT's for me.