In reality, you've done well to get 54.
I have purchased Super G (108Mbps) products. This includes:
Netgear DG834GT Router
Netgear WG511T Card
Netgear WG111T USB Adapter
But I can't get any of them to 108Mbps speeds. I have updated all the drivers, changed the settings to Auto 108 and ch 6 and only get 54Mbps on full signal strength.
If someone has the solution to my problem, please help me out.