Bleyrad, you're talking about apples and oranges. The 603's are not a matched stereo pair, and I wouldn't even consider them for an X-Y pair. If I wanted 1 small diaphragm cheap, I'd buy an Oktava MC012, just for the pad and the ability to add other capsules. The NT5's are cardioid only, no shock mounts, no pads.
Even if the sound quality is compareable, the NT5's lose massively on versatility. When the price of the shockmounts and a decent case is factored in, NT5 loses big time. $300, no pads, no shock mounts, cardioid only. I have a pair of MC012's that *are* matched, and they cost me $424 plus the shock mounts. If I was doing that right now, I'd wait on C-4. Basically, The Sound Room's Oktavas, NT5, and the new C-4's are the only game in town for a matched set under $500, which the 603's just aren't. Of those 3, the C-4's offer more features for less money by far than the competition. The only way that won't happen is if the mics suck. But knowing Alan Hyatt, and Brent Casey a little, they won't. I know Alan well enough to know that he won't bring the mic to market unless it has a clear advantage over the competition in performance vs. price. That not only means that I'm comfortable suggesting that it's worth a short wait to check out these mics, but that I'd trade my Oktavas for a pair of them right now, without ever hearing them.-Richie