I just took a look with the Buffalo Classic USB and certainly it is an interesting SNES inspired controller, to think it has a built in turbo button too.
Agreed having multiple controllers is a pain, especially I have to plug them in and out from time to time.
Mapping controllers on Retroarch is indeed a pain as well, especially trying to map N64 controls.
Last week I bought a N64 inspired controller from SAFFUN, tried mapping it on Retroarch. After a good 10 minutes, I gave up and went with Mupen64plus with Rosalie’s Mupen GUI