Status update:

The DGND3700 was a consistent failure with the hard ports going belly-up when we got home from work every day. Reboot fixed, but that ain't right. I boxed it back up and returned it, and went back to the DGND3300.

I was poking around the configuration of the DGND3300 and observed that when you've got it in simultaneous dual-band mode, then you get 802.11n at 5GHz and 802.11g at 2.4GHz. Since 5GHz is basically unusable anywhere in the house where we normally hang out, I went to the 2.4GHz-only mode, which gets me 802.11n at the 2.4GHz band.

Also, today my Asus RT-N12 arrived and, after a firmware upgrade, is now serving as an AP downstairs in the home theater rack. The difference is stunning. This thing has a really, really strong signal. I'll have to chime back in later on when I have a sense of whether it runs cool or hot.

I'm going to stick with this for a while, at least until I sort out what, if anything, was failing with the old DGND3300. If/when that gives up the ghost, then I'll pony up for the DrayTek.