List of Comcast speeds in Chicago, IL (North side near I-94: Addisson/Irving Park/ area)

Could someone help verify the listed speeds for the different services
for Comcast:

Performance - 20mbps (Customer support is claiming it's now 15mbps)
Blast - 30 mbps (Customer support is claiming it's now 20 mbps)

I was getting 20+ download speed tests on Performance which is correct.
When I told customer support I was getting half (because of packet loss)
they brought this other information to my attention

The folks in the forums at are generally on top of this like
a hawk and are probably a better resource than here. For what its worth,
Comcast often provides temporary speed enhancements for the first so many
bytes in x seconds, ("powerboost"), which can often throw off short
flash-based speedtests.