my PC, Macbook and PS3, all within a 2 meter stretch are all different speeds on my home network, all are wireless.
My PC is the slowest, 802.11g adapter - youtube doesn't buffer well to begin with, freezes for a few seconds then buffers fine, web pages take a while to load. Keep getting disconnects and high latency in BF3 and SWTOR
My Mac is on the desk, next to my pc, prolly 802.11n - Youtube loads straight away. Pages loads super quick
My PS3 is on the floor under my TV which is prolly 802.11n as well. Never had a disconnect playing online.
I've tried port forwarding, firewall off - both router and PC, restarting router, restarting PC...
It cant be an ISP problem seeing as my Mac and PS3 work fine, but I am on BT Broadband and using the Homehub 3