I've got one and I like it. I'm the past I've used a sansamp, a paradriver and a VT bass, which were ok for a bit, but all sounded a bit thin at times.
I've only noodled around at home using the SE software but gain levels seem to feel a bit deeper, as in more headroom and the using a pinch of the built in comp seems to really make the tones enjoyably squishy, like kind of like a big power amp section.
This week I've been
enjoying the Sansamp RPM and Fridge models a lot, also the fender twin and Princeton guitar amps are a lot of fun. I've yet to load up much more on it.
I'm looking forward to trying it at volume and seeing how it fares next to a drummer. If it holds up at louder volume I might not need an amp anymore... ... I mean, until I decide I change my mind again and start to daydream about 810 cabinets and heavy power amps...