It really isn't. I can still get the job done, but Cialis really riles a man up.
Viagra will give you a raging boner - the kind that can punch a hole in sheet rock - but you're not horny.
Cialis does both. Your dick is on Defcon 5 "This is it boys!" level of rising to the ocassion, and your mind shifts into ass slapping, "Hair Pulling" freak mode.