D-Link DIR-615 and Netgear WN121T transfer speeds?

Hi,

I'm just trying to get a general feel here and see if I'm doing something wrong or if this is just how things perform. I currently have a Buffalo WHR-HP-G54 router hooked up as my primary router with the D-Link DIR-615 "piggybacked" onto it as a secondary router. Now, everything is working properly on the network, computers can connect properly to either router and can acess all network files and printers. The question though is about the speed of the network.

I used a 1048574KB VOB file as the test and these are the results;

1:53 LAN
3:56 Wireless N
5:55 54G

I used a free utility called online eye to monitor these speeds.

The LAN hit around the 80 Mbits for an average, N was about 37 Mbits and the G was about 22 Mbits. Was I wrong to assume that the N could deliver MUCH better results than this? Even the G was using 41% of the bandwidth while the N was only at 12%. The routers are both using WPA and are set to channel 1 and the other is 11.

Any thoughts on this would be greatly appreciated.