I've had a 14x Aran, Bucc, and DB...12x paladin, dawn, BaM...Aran is very involving, while you only have one real skill there is so much strategy required to make the most of it. You have to be very focused in order to play Aran efficiently, there are multiple fun builds (speed for instance) that change it up alot, and all in all Aran becomes whatever type of character you play it as. However, even with fast paced builds I found it very slow. My main complaint with aran was having to go through 3 attacks in order to get to your real damage, which by then was usually a waste. Aran cant just jump into a map and start killing without some sort of map strategy or in good situations, simply a really high spawn.
Bucc is slow and boring, I enjoyed it greatly. It's amazing how slow Buccs can move even when you're using ST and dash, dragon strike has an annoying split second of delay after each attack that ruins the rest of it. Barrage takes a good 5 minutes to use, but the damage is so cool looking and Bucc is very flashy. The coolest thing about Bucc is the invincibility frames from corkscrew and barrage. You really learn how to work your skills and it adds a new dynamic, seeing how long you can go without getting hit. I'll be making a new Bucc once UA comes out
I prefer fast and flashy chars, neither Bucc or Aran really fit those in my opinion, it's all about BaM right now and DB before that, Shadower even can be a blast. I suggest trying your BaM out with a fast attack weapon. Training is fun if not just for the fact that you obliterate the entire map in the time it takes a Bucc to use barrage once, or an Aran to get off 1 combo.
Good luck on your decision wallee! Hope this helped