I have a SansAmp PSA-1, and
a Boss GT6-B. Both have given me good results. Mostly, I got these units for live applications. When I need lots of power, or the ability to switch between a variety of different sounds on the fly, I'll hook one of the modelers up to a power amp, and drive my speaker cabinets with that.
For recording, pretty much anything is up for grabs. I think that there is a line out of every bass amp that I own, so it's easy to plug one of those in. The amp models in the PSA-1 and GT6-B are certainly good enough for recording, and I wouldn't hesitate to do so, if there is a sound that I can't quite get with one of my regular bass amps.
One comment that I would make about the PSA-1 is that, while the thing is incredibly versatile and can do just about any tone you can think of (it models guitar amps, too), it's certainly not very intuitive when it comes to fine tuning your tone. In the time it takes to dial in a particular sound that you're looking for, you could have hooked up a regular amp and mic'd it. So, it's only a good choice for recording if you're in a situation where you are NOT paying big bucks per hour to lay down the bass tracks. In that sort of situation, you'd probably be better off with a SansAmp BDI stomp box or an RBI. The Boss, on the other hand, lets you locate and fine tune your tone very quickly. It also offers a digital out, which is a nice bonus.