...high alt raids generally at cruise speeds...
What exactly is the "cruise speed" of a formation of B-17s or B-24s flying at 25,000 feet--in True Air Speed? I'll tell you that for a loaded B-17 at that altitude, it was around 240-260 mph TAS, based on a planning chart I found on Zeno's website. Now, once the weight was gone, they could pull a little power, but their speed would have stayed pretty similar due to the decrease in induced drag, which at those weights and altitudes is pretty high.
On long missions, they replaced bombs with fuel. That's why the B-17 would carry 5,000-6,000 lbs. of bombs instead of what it was potentially capable of. The bomb bays were rarely "cubed" out.
I appologize if I sound curt, but I've argued this pretty much every time Krusty starts one of his bomber rants, and its getting tiresome.