I use a QVS PS-2 to USB adapter and agree with the newegg comments. For general typing it's not too bad, although if I have Shift manually held down and type a bunch of keys, after the third or fourth key, it unshifts. It would not be acceptable for gaming, though. I tried it on battlezone and if I held the key down, then released it, then pressed it again, it will not register as "down continuously."
FWIW.