I guess if we're to decide if an aircraft is 'good', there has to be stuff besides how 'nice' it looks, and let's face-it, back then , Military aircraft were designed to do a job with what had been learned of aerodynamics by that point - I've been reading-up and the P.108 was a pretty advanced aircraft at the time. - The Lancaster had evolved from the Manchester, and that is a parallel to the He177, where the engines of the Manchester were the RR Vultures; trying to marry two Merlins together, not unlike the He177 with its DB engines. They went on to make it 4 engined etc.,
BUT, the crux of it all rests on their respective performances and what they achieved in the War - The B17 was a reliable, well-armed and crewed aircraft, their total tonnage of bombs dropped were roughly equal to the Allied night-flying counterpart, the Lancaster, and because they succeeded in flattening the enemy, the credit really goes to them and those that flew 'em. They were the thoroughbreds that won the War - There were others that helped too; - B24, B25, B26, Stirlings, Halifaxes and THE Mosquitos, but this threads heros were B17 and the Lancaster...