Acrobats have an easier playstyle, as playing up close comes easier to most people. That being said, you'll have to be dodging the entire time you're doing anything, since archer's aren't amazingly armored. A class like acrobat tends to be a dream class for a lot of MMO gamers though, since they've got an in-your-face way of playing, but still have the option to maintain a distance.
The difficulty behind playing a sharpshooter is that you're required to actively aim the entire time, which can be problematic (especially on bosses such as Scarlet Scythe, who is skinny and moves around a lot). That being said, the DPS is outstanding (I've been told that sharpshooter is capable of having the highest DPS in the game, in the right hands of course :v). Also, it's not like you can't mix the playstyles of the two classes a bit anyway. I play sharpshooter, but I have a tendency to play at a mid-range, so that I can make snap decisions on whether or not to rush in and cast a debuff or fire a frag shot or anything like that, or if I want to pull back and launch a magic arrow, or even if I want to do a tumble shot (keep in mind I'm building toward an artillery, the magic-based damage sharpshooter class).
Really though, the way I see it you could play either and gear it however you like. No harm no foul. Just remember that archer has one of the toughest learning curves of all the classes in-game. Have fun with it.