EMD E-units weighed somewhat more than a comparable F-unit - 290,000 to 315,000 lb or so, vs about 245,000 lb. However, E-units had both less adhesive weight (because of A1A trucks) and higher horsepower than F-units, making them more prone to wheelslip. That's why railroads in mountainous territory (such as DRGW) tended to use boiler-equipped F-units rather than E-units on passenger trains.
From a maintenance standpoint, while both series were very reliable, the single 16-cylinder engine in the F series would have required less maintenance (on a locomotive-per-locomotive basis) than the twin 12-cylinder engines in E-units.
