the only thing that concerns me about R20 is the amount of modding required to make it modern (tour gearing) and decently serviceable when things break. To make it really touring worthy, we're looking at spreading the rear to 130 or 135mm, adding a derailer hanger, adding canti bosses for modern 406mm wheels, swapping the fork and chasing and facing the BB to 68mm or 73mm and english threaded.
otherwise, yeah, it's a nice frame to build around.
I'm just talking about the overall durability. Plenty of threads here about other frames cracking, my Dahon makes creaking noises I can't ID, SA8 hub on my DT is unreliable, Strida 3 had is own unique problems....R20 platform is still the standard. Certainly, brakes and whatnot need to be upgraded, but still...