I've used both quite a lot and the Rohloff is definitely better. Having said that, I probably wouldn't spend my own money on one. I never had a failure on the Alfine that made the bike anywhere close to unrideable, although my knees were quite regularly bruised from having the gears slip when I was out of the saddle, banging in to any manner of oddly shaped angles on the cockpit of a Bullitt. An Alfine needs more looking after than a Rohloff and won't give you the same range of gears or ride as nicely but is pretty much fine.
I've used both quite a lot and the Rohloff is definitely better. Having said that, I probably wouldn't spend my own money on one. I never had a failure on the Alfine that made the bike anywhere close to unrideable, although my knees were quite regularly bruised from having the gears slip when I was out of the saddle, banging in to any manner of oddly shaped angles on the cockpit of a Bullitt. An Alfine needs more looking after than a Rohloff and won't give you the same range of gears or ride as nicely but is pretty much fine.