I believe the difference between the brilliant Lancaster and the B-17, the most magnificent aircraft to ever fly, is that they were designed in different "eras" for different missions. The B-17 was designed around 1935(?) as a "patrol and defend the coastline" kind of plane for a theoretical war. The Lanc' was the result of an ongoing evolution of the Manchester (How much crap can we dump on the Baddies?) with actual war experience as part of the Lanc's design.
I hope we will be hearing from the folks who actually know what they're talking about.