Actually there are a third type ... Nutted. These are simply solid axles with a 10mm thread on each end, that are held in place in the dropout with nuts.
Most of my bikes have been QR (Road / MTB) or Nutted (Touring - Including my Dawes Tandem), even my 29er "Mountain" bike, which was my first disc braked bike, has QR's
QR's are great on Road "racing" bikes for the ability to swap a wheel at speed in a race ... other than that I can't see a benefit, well apart from not having to carry a spanner to loosen your nuts
Rohloff offer all three options on thier hubs, so you can choose the hub that best suits your purpose. Having said that on the Raven Twin I have a QR hub even though the Nutted hub is the suggested option from Rohloff ... I just took Robins advice when speccing the tandem. I was already pushing my luck asking for the disc brake version over the non disc which was in the listed spec.