ADK mics are awesome. Both me and a friend have the ADK mic thats similar to the Neummann U87 and we are both in love with them. We just used them both today to record a drum set. We only used the two mics to record the whole set and couldn't have been more pleased with the way it turned out. I am a huge fan of these mics! They aren't the best for micing cabs but for vocals they rock! I am a firm believer. I think i paid 300 for mine where as the Neummann would have cost me an arm and a leg. Very Good Mics!!
I've got a sequential pair of A-51 LD condensers. I did a 3 way blind test for a vocalist in my studio a couple of weeks ago with the A-51, an SP C-1, and an AKG 4000. For his voice, the A-51 had the best response. He doesn't have a particularly powerful voice, and he's a little nasal. The A-51 does not have the "sheen" that the C-1 has, and that worked pretty well for his voice.
I've also used them for acoustic guitar recording, and they sound nice. I've got a pair of Octava MK012's, and they are not significantly better than the ADK's, to my ear.
Good mic for the price-I got my pair on eBay for $200.