We have 4 of them and have complained of the same problem. Ours seem to go a lot slower than yours, and we have been unable to figure out why. I have two decorated for Illinois Central and another club member has a set decorated for Union Pacific, and they all run way too slow for passenger train use.
I've even been trying to find out if an upgrade chip would help, but no one seems to know.
I have the City of San Francisco E-6 A-B-B set, and though I'm DC, I've never tested them 'full-out' because of both the pretty constant curveature and grades (up to 2.4%) on my layout. They appear to be very smooth runners at the maximum speed I use (perhaps 45SMPH), and good pullers.
However, I'd be interested to see what others are able to do with these BLI E-s, simply if I ever have an opportunity to run them full out on someone else's layout. I'd like to hope that they're capable of the 100+mph that the prototypes were, at least on long straighaways. One would at least hope, right?
Tom
Tom View my layout photos! http://s299.photobucket.com/albums/mm310/TWhite-014/Rio%20Grande%20Yuba%20River%20Sub One can NEVER have too many Articulateds!