@popo7676: I don’t want to split hairs, but the 802.11g standard supports a maximum bandwidth of 54 Mbps. The only way to get more bandwidth is to add proprietary extensions to the standard. Fast Ethernet supports 100 Mbps. Therefore, you can shove more data across an ethernet cable than a wireless connection.
My experience with cable broadband internet is that it ranges between 200 Mbps and 450 Mbps of bandwidth available. So if you have 5 people using it all at the same time you can pretty much expect slowdowns. The throughput is influenced by the speed of the server you are connecting to also, of course.
You’re correct that you can’t tell if you’re just surfing the net. However for streaming media and file downloading I notice a huge difference.
I also notice a difference for rendered 3D graphics over the internet. If I play certain games with my wireless AP 2 feet from my computer I still don’t get as good of performance as if I plug into the router directly. But this could be related to reliability, as you were saying.
@jonbo2: If someone is plugged into the router directly and you are all trying to download files, it’s possible that the person with the direct connection could get more throughput due to a higher max bandwidth restriction and more reliability. However, in general routers have load balancing features that attempt to provide bandwidth to all connected users (which is why it slows down if you have too many people).
You could try getting a better router. With wireless routers you often get what you pay for. And it’s absolutely true that too many people using the same pipe will slow it down. However, for home broadband I would say having two routers would not benefit your overall experience much (since the cable itself becomes the limiting factor). But you might get better performance from a better quality router. I saw this having no idea what kind of router you currently have.
Also keep in mind that your distance from the communication switch that your cable connects to, and their distance from the nearest internet backbone will influence your apparent speed. Corporations put their fat pipes near backbones for a reason.
Cheers.