You will like the Airbus 330's, brand new, audio video on demand in every seat. The 757's domestic are nothing special. NW flies 330's LHR-DTW and LHR-MSP. They also fly a 757 transatlantically configured LGW-DTW.

(those layover times are really bad, by the way, you might want to look at buying a 60 day world club pass for 85 dollars to help pass the time)