I think that is the best you can do (well i am out of ideas now), perhaps if you go closer to the antenna (for testing) will give you much more speed
When i was with VM 100mbps package ( i am please the 2830 does get almost 160 speed) at 1,5 m far was getting 80+ ... going about 8 meters was falling dramatically

I am not sure with the overhead, The program called inSSIDer will show overhead for channel issues, If you search it "wifi overhead" should show some theoretical calculators

I did blame the 2830 range but to be honest ... perhaps the 2830 working so hard to get the full speed of 160mbps, has slow down the CPU & so the wifi powered driver
When i was getting 80+ i was near by (1.5m & all wifi settings by defaulk) plus the speed i had (100mbps) was close to its specs (90mbps throughput to its firewall)
I think with that speed (160mbps) the 2830 working at its max but again also it does have some some shorter range by its default

I would say (never test it when i had that high speed as well) to disable wMM at wireless (similar to QoS) ... DoS and disable the firewall for testing if you see improvement

banjaxt wrote:

Thanks for your advice - done all of the above. No SSID limits as it was factory default on most settings.
I also changed from WPA to WPA2, which apparently can carry higher throughput and the speed almost doubled to about 40MB via WiFi.
I'm less than 10ft away from the router so I figure there must be something else I can do to get a better throughput..?

Thanks for the WPA2 advice. That has given me a substantial speed boost.