3.5MB/s is damn good. Thats higher than advertised. They doubled download speeds from 1.5MB/s to 3MB/s, so your getting pretty good down speeds.
With my tweaked Registry, bandwithplace.com wont even allow the test for me anymore lol. It says the speed is too high.
I score about 4150KB/s (a little over 4MB/s) on PCPitstop.com.
Your 3029KB/s from PCpitstop.com means 3 Megabytes, or a tad more actually. So thats right on

They promised to double, so anything 3MB/s or over is great.
1000 KB's = 1Megabyte
If you really want to test, and "tweak", go here and read. It really isnt that hard if take your time to read up 'bout it.
http://www.broadbandreports.com/stest
You may have to join the site in order to use the East Coast test server, but this test server is located where it can reach major backbones via a DS3 connection (DS3 is 45MB/s). Make sure you have Java installed too if you wanna use this site. If you dont, they have a link to it.
Actually, just go here....
http://www.broadbandreports.com/drtcp
Download DRTCP, open it, and in the TCP Received Window box, put 36956. then go back to PCPitstop and retest. You should get 4000KB/s for download speeds, maybe a little more.