What this does is puts your phone line digital from the phone companies central office to the cabinet near your home where that system is located.
I live about 8 miles from my phone company but the SLICK is right up the road. I get a consistent 48-49K connect speed on dial-up verified through several checks. My dad who lives down the road from me is not on that system and gets 22K tops. His phone line goes straight from his house to the central office.
Another good possibility is you may have line noise on your phone. Pick up your phone and dial a couple of digits. Listen for any popping noise or a hum in the line. If you hear it then that can drastically cut down your connect speed as well. That is likely a phone company issue.
Would`nt a second phone line increase the cost to the point equal to a satellite system?