I had a Santa Cruz slick. I believe they were the first to do it? Either way, it sucked and was stupid. The board weighed a ton, and Santa Cruz was still doing fishtail shapes way after boards started to evolve into the popsicle stick we know today.
I was cruising around with some kid at this gallery yesterday, and I was bewildered at how he'd skate his board either way, without any regard for which end was the nose or tail. He was pretty decent, so it was surprising to me. I definitely notice a difference between the two, and do certain tricks only off either the nose or tail. Shove-its and any varial trick has to be off the nose, so I land with the tail under my back foot, and I only feel comfortable doing kickflips, ollies, 360 flips, etc off the tail. Any switch trick is off the nose, so my normally forward foot is still doing tricks off the nose, like a nollie.