Random observation from when I replaced my D-Link DGL-4300 "gaming router" plus cheapo Motorola DSL box, with a Netgear DGN-2000 (all-in-one DSL + router + wifi).

The D-Link had gigabit, but not jumbo packets. This was still a significant performance feature when I was running my ReadyNAS file server, since replaced by just adding more disks to my Mac. The new router is "only" 100Mbit, but that hasn't been a problem.

The D-link had 802.11g with one external antenna. I had replaced that with a larger, longer-range antenna, but it still didn't reach from one corner of the house, where I had it, to the other corner. (No biggie. I got a D-Link DAP-1522, which has a four-port GigE switch and is a not-simultaneous dual-band 802.11n access point and connected that via wire.)

In my new world, the Netgear, with two antennas and 802.11n (2.4GHz only) covers the whole house, rendering the DAP-1522 access point not terribly necessary any more, although I suppose it means that devices can lower their transmit power when they're near it.

I will point out that ditching the Motorola DSL modem for the modem built into the Netgear was a world of difference. Much more stable connections.

With regard to dual-band, consider it to be a non-feature unless it's advertised as "simultaneous dual band." My DAP-1522 has a software switch for 2.4GHz vs. 5GHz. I tried it both ways, talking to my MacBook Air. At 5GHz, with less than ten feet of air between the laptop and the base station, even surfing the web didn't work well. Things like YouTube were hopeless. Switching to 2.4GHz, it worked like a champ. I later met a resesarcher who does antennas and asked about why this could be. Simply, they're most likely taking an antenna designed for 2.4GHz and shoving 5GHz through it. That gives them a checkbox, but doesn't yield a workable feature.

One caveat about the Netgear: when less than six months old, the wired ports all fried themselves, high packet drop rates, etc. Netgear shipped me a new one, which is now running just fine, but the router is quite hot to the touch. I fear it's not going to last very long.