Well, since I'm mentioned in this thread, I'll respond from the road (I'm in Toronto at the moment).
Self-noise; there is some self-noise as Teddy mentioned, however for most things, including acoustical, this doesn't present problems. However, if you are trying to make nature recordings or record where there will be lots of silent passages, then you might want to forgo these mics.
Price; there was a huge price increase when the investors of Earthworks took over and kicked Eric out. This was a huge mistake in my opinion, but according to a couple of people I know who claim they have some inside skinny on things, they looked around and saw that the mics they wanted to compete with were priced much higher, so they decided to price the new EW mics in that same price range.
Sound; as mentioned when recording with these mics, you can get some fabulous recordings, or some real duds. The reason is the low end drops off at around 100 Hz by about 6 dB, and continues to fall. At loud rock venues, I find that this can sometimes be a blessing because the bass always seems to overpower the recording. But, sometimes you end up with recordings that just lack enough bottom end to make a recording sound great. When I ended up doing to fix this was use a pair of QTC-1/QTC-40 along with the SR-77's and mix those with the SR-77s. I did this with initially with a field mixer (Wendt X4), today I run multi-track and mix back home where I can really monitor things in a better environment.
Are EW mics worth it? I'm the poster boy for them, I own 4 sets of their mics (2 QTC1/QTC40, and 2 SR-77/SR-30 sets), plus I bought a pair of thier Sigma 6.2 studio monitors. I think their results speak for themselves, but I also think EW made a bit of a mistake with the new pricing structure. They use to be the best bang for your buck. Today I wouldn't say that is accurate, but they still make a great product that can compete with some of the bigger names in the business.
Wayne