I have a Shimano Alfine 8 speed hub that has been absolutely bombproof. I used it on my mountain bike for challenging off road riding with a lower than recommended gear ratio (more torque into the hub) and never had an issue. THe only maintenance I ever did was (a) disassemble and dip in ATF as recommended by internets people, and (b) occasionally disassemble the 'cassette joint' (external cable attachment mechanism) and wipe it clean.
THe main bike it was used on has vertical dropouts and so I used an old rear derailleur as a chain tensioner. And because I never bothered to remove the extra large chainring from the crank, I could stop and put the chain on the large ring by hand - I called it my 'Greasy Fingers Overdrive'