Thinking of the presently running string about gear ratios I have started wondering:
Exactly what speeds do you ride (top and average) while on the tour? I've seldom found myself going over 25 or so when carrying a load regardless of the incline. For one thing, I don't feel comfortable knowing that loaded touring bikes are a great deal more prone to speed wobbles from flapping packs than a road bike. For another you are severely limited in your stopping power in the first place. The very best you can expect from a bike is to be able to stop about half as fast as the average car.
Riding on flat roads I usually ride around 15 mph but when touring with other loaded tourers it's been more like 12-14 mph most of the time.
If all of this is the case, why would you want an 11, 12 or even a 13 tooth cog?
Knowing this I think that those tourers who ride 44-48 tooth big rings know a lot more about it than those discussing 52-12's.