I personally use all whole leaf hops. Mainly because I just prefer unprocessed ingredients whenever possible. Secondarily, because my set up was created with leaf hops in mind, pellets leave me with a clogged mess.
FWIW, pellets give a few percentage better utilization over leaf, so assuming the same weight and AA%, the pellet beer would be a touch more bitter. Flavor and aroma are obviously much more subjective to personal preference.