Quote from illiquid:
But again, does high bandwidth necessarily decrease latency? If I upgrade from 10mb/s to 50, will my ping to the exchange servers go down proportionately? [/B][/QUOTE
No I don't believe it does. I have Comcast in Denver with the regular docsis 2.0 16 down and 2, and my pings to Chicago are 26-32 ms, that's damn fast for being approx. 1000 miles away. I have power boost and I can get speeds boosted to 25 down and 9 up with the same ping times.
I have never tried the ultra speed ( docsis 3.0 ), but if you decide to get the Motorola SB 6120 modem if your ISP supports it, very good reviews.
If you live in highly dense area, which mostly likely you do, there could be crappy splitters on your line, worn co ax, old infrastructure in other words. My subdivision is new less than 6 years old, all new infrastructure.
This may help you read this page and check you signal strength
http://www.speedguide.net/read_articles.php?id=1197
Good luck.
Dan
Post Edit: Have you had the tech out to check you line? I would threaten to cancel unless the fix it.