You'll read a lot of good things and bad things about this mic, especially on gearslutz where they can get amusingly emotional. A small but vehement crowd says the newer version (ai) sounds bad and nothing like the cherished vintage U87. I've owned a few vintage U87s, and I actually prefer the new ones (although they sound very similar). The older version might be a bit more forgiving due to the distortion in the upper freqs which can help mask a singer who is not on pitch. But if you are a good singer, you'll want the newer version: lower noise floor and more accurate picture.
Here's one thing that just about everyone agrees on with regard to this mic: It doesn't always sound the best on a given source, but it always sounds professional and good enough -- and your track will sit well in a mix. It's very true. I can find better mics for my voice in this price range, but that mic might sound bad on the guitar or something. So the nice thing about the U87 is that it sounds acceptable on everything. What have I recorded with it? Lots of things: vocals, guitars, drums, sound fx, claps, hand percussion, piano, melodica, vibraphone, and more. It always sounds good!
