I have flown them both and I am on the 757 now. The 'bus specific fuel consumption is better than the 737 300. I don't know about the 737NG. Cruising at .79 at 350 to 370 I seem to recall fuel flows around 2800#/side, but it has been over 4 years since I have flown the bus. The Bus is faster, the boards work better and the cockpit is more comfortable than the 737. I, too, used to turn the automation off and fly the jet, much to the shock and horror of my F/Os, most of whom clicked the A/P on at 500' and off at 500'. I also used to do MX checks and got to fly it in direct law for real.

Now the 757 - that's a whole different animal.