Production numbers alone don't really tell the whole story. B-24's were a later design, so it is logical that it should have been an improvement over the B-17. One improvement was to simplify the structure of the aircraft to make it easier to produce. While USAAF leadership preferred the B-17, those producing the B-24 could make a lot more of them given the same time and money. The wing design of the B-24 was both its greatest strength and weakness. The high aspect ratio meant better high altitude performance (less drag while sustaining 1g). This allowed greater speed and/or payload. However, the longer, thinner wing was built for aerodynamic efficiency whereas to this day Boeing generally makes their aircraft much stronger than any specification requires. Unfortunately, that extra strength costs weight. The B-24 also shaved a few pounds by carrying fewer guns/ammo/gunners. The fact is, both bombers did a great job. To say which one was really better, don't compare standard flight performance figures, instead look at tons delivered versus sortie rates versus losses. Was the B-24 significantly less rugged than the B-17? If there is a significant difference in the loss rates (i.e. the B-24 got shot down a lot more times for the same number of sorties), is this difference high enough to cancel out the cost/production advantages of the B-24? I don't know the answers to any of these questions, but those are the ones that must be answered to eliminate bias. Personally, I have always loved the B-17 for both its looks and its guns. The B-24, especially the later versions with the nose turret, looks purely utilitarian compared to the graceful lines of the B-17. IMHO, the B-17G looks great with the chin turret, though the B-17F is truly the sleekest looking version. I love all aircraft, but the B-17 has always been one of my favorites. On paper, the Lancaster is much better than either the B-17 or B-24. But it is hard to draw conclusions since the Lancasters flew at night