Drag is proportional to speed squared... the difference between 14R's 18mph and the above 22mph would then be:
aero tuck: 10.9N
drops: 16.2N
hoods: 17.4
up 2cm: 18.4
My tests would have been roughly the same as tuck, drops and up 2cm. Alex Whetmore, who did those tests you quoted, agreed with everything I found in my tests.
I suppose it's like trying to reduce bike weight: There isn't one big thing that is going to make a massive difference by itself - you basically have to do everything, and a lot of small things amount to something useful. So going to a more aero position would make you a small amount faster, but don't expect a miracle. In fact if you are not comfortable, you'll end up going slower over an hour.
You are one powerful dude if those differences don't amount to much for you!!!! Using those numbers at 18 MPH the marginal power requirement for drops over tuck is 42.6 watts, hoods over tuck is 52.3 watts, and up 2cm over tuck is 59.5 watts. Any of those is a significant chunk of my power output. A set of $50 aero bars and you can hold that tuck position pretty comfortably.
Back in 2001 or 2002 Bicycling Magazine did a "bang for the buck" assessment of the most cost effective way to buy performance on a bicycle. Aero bars won hands down. The drag force goes with the square of speed, but power required goes with the cube of the speed.
Speedo