The Solidtube is unique in that it has gone from being an overated mic to an underated mic in about 5 years. It started as a $1000+ high end vocal option, and competition from the likes of Rode NTK and Studio Projects T-3 moved it onto the back burner. The conclusion was, it was a lousy $1000 mic. It is *not* a lousy $400 mic. It has a stupid internal pop filter which makes it sound distant, dark, and muddy. It can (and should, IMHO) be removed, and the difference is dramatic.
Solidtube is a very good mic for gritty, loud vocals, and maybe not so good for quiet, pretty stuff. I think they wanted to design the mic to withstand pretty high SPL's (loud stuff), and they did. In exchange, I think the mic needs you to yell at it a little bit to get it going. Excellent for the blues, or a screamer, or a belter, and probably for an opera singer, for the same reason. If you have a "delicate" voice, I'd pick another mic, but if you're ready to yell at it a little, Solidtube can produce remarkable tracks.
Removing the stupid pop filter changes this somewhat, and makes it sound a lot like a Rode NTK, but with better high end detail, a bass rolloff, and a pad. The multipin cable that comes with it is a little delicate, so if it's a main vocal mic for you, I'd keep an extra cable around, just in case. If it's in good shape, for $400? Shit, yeah.-Richie