I have the NX2 running with a Streamliner 900. I haven't had problems meeting my volume needs so far, but I'm pushing quite a bit of power into the cab just to be heard. My band has a moderate drummer and 1 very loud guitarist and I'm up past noon on the gain, pre volume, and master just to be heard.
I'm still figuring out the EQ on the streamliner and finding my place in the band, but right now I'd wished I had gone with something a bit bigger. It all depends on what your needs are. We are playing hard rock, similar to 90's grunge ala Soundgarden, Alice in Chains.