Everything else being equal (meaning aircraft condiiton, service, seats, etc.), I have always found the 757 to be far more comfortable that the 737. I know the seat pitch is often the same and the fuselage diameter is also the same, but the 757 always somehow just feels more spacious. Maybe it is the fact that it feels overpowered on take-off, more like being on a luxury coach than the school-bus 737.