Yep, I keep my cache and cookies cleaned out... in fact I block a lot of them. When I change pages I see about a half dozen different adware, google analyitical and several cookie monster programs that read and write cookies. So there is a lot of activity before a page even gets to load.
I tried from another computer that I use pretty much to only VPN into my work through a secure tunnel and which I rarely do any open browsing with, so it's not as heavily protected against internet nasties as my normal computer. I did the speed test and got over 25 MBps upload and download on it and accessing this site was faster, although still not up to par with other glass and photo forums that I frequent. So it appears that it might be all the adware that is hitting my computer and my firewall and intrusion protection programs are working extra hard to block. Most people that don't run a firewall don't realize just how much information gets pulled off their computer and the number of tracking cookies that get deposited to be read by other cookie monsters.
Come to think of it, I think I started really noticing the slow downs about the time the Oscar Myer hot dog ad started appear.