I've used SSB a lot (when I need brass that is) and I like it a lot. If it's not the main brass in a track, it often ends up doubling or performing supporing tasks still.
I'm far from being a good brass writer though, and I don't especially write demanding brass stuff. Nothing loud or epic, which I don't think would suit SSB anyway. It excels more at the traditional orchestral, or warm choral, or regal sounding stuff.
It blends very easily with my other Spitfire stuff, or anything really that you've got some reverb on. It has a warm smooth tone you don't easily get from other libraries. Low dynamics are great for choral stuff, which other libs can't match.
Some of the layer transitions are not as good as they could be in the longs. And the shorts at the higher mf to ff dynamics on trombones and trumpets can jump dynamics too quickly, which is annoying. But a lot of brass libraries have that problem.
It can be a bit muddy sometimes, particularly I find with the horns. You can EQ that out a bit if you need to. If you want a clear direct tone, these aren't it. But really, it's that diffused hall ambience that's so damn fantastic about them... you really need that sometimes for a good brass sound. That Air hall just does wonderful things to brass.