my desire to have simultaneous dual band. The D-Link is "switchable", but in practice it works fine at 2.4GHz and is a total useless junker at 5GHz. I'd like something better.
Why do you prefer dual band, exactly?
On that note, are the two wireless signals (D-Link and Netgear) on different channels or even on different frequency ranges (2.4 one, 5.0 the other)? If not, that may be the problem.