I would go here http://www.dslreports.com/faq/8237 and read through these guides. They are very detailed and accurate. The 4000 is a little tricky for networking, but a great one when you get it done. STAY away from the 6000. You will not get the speeds from it like you can with the 4000.
Frank
The weather out here in Va and Md (where NOC is) sucks today. I would give irt time for the storms to pass and check again.
I know it sucks big, and I only have two more months on my contract. Adelphia is finally here