Well, initial indicated connect speeds don't really mean THAT much - Rockwells like the Supra connect high and only train down, but USR's can connect low and train up AND down as needed. Run a test - download a compressed zip file from the same server (preferably your own webspace) with both machines, time it, and do the math. It's throughput that really counts, not just the numbers on the icon. Before I got DSL, my USR only connected to EL at 37k, but it would train up to about 45. (USR's have a way to check this - immediately after disconnecting, open Hyperterminal and issue the ATI6 command, it will tell you the speed it connected at and the peak speed during the last session) Funny thing, but now that my line has been conditioned for DSL, when I *do* use dialup, it connects at 50.
If you are interested in line noise tests, here's a good read:
http://www.modemhelp.net/linenoise/noise.shtml