Yes, if you haven't already, do check out the Mic forum- there is a lot of discussion about the B1 and SP mics in general over there now.
To answer your question- yes, the SP line is generally highly respected as an excellent value. They are good mics for a good price. Like any mic, though, each model is better for some things than others, and there are more and more "excellent value" mics out there in a comparable price range.
I've personly only used the C-1, which I greatly enjoy as a main vocal mic. It works for acoustic guitar, too, but not as well as some small condensors that I have. I can't speak for the B1, but I'm pleased with my SP mics.
Take care,
Chris