I think its impossible to drink a can of beer or pop in less than five seconds (without shotgunning it). I did the pop mile once and basically just tipped the can upside down pouring into my mouth (at least on the first lap). It definately took more than five seconds, probably more like 8-10, then assuming the stopping time, grabbing and opening the can and completeing the transition zone 9about 10m) it took about 13-15 seconds minimum time per lap. (Anyone that claims they ran under 5min is full of crap)
Pop is definately harder than beer. When the beer milers get down, they are just starting to feel drunk and happy. When I got done, the caffiene and sugar had gone from my stomach straight to my brain and all I wanted to do was find a nail gun to shoot into my temple to get the migraine to stop.