The NX Edge Style Banshee is the best non-scale Banshee in existence and nothing can change that fact.
The gleaming V-Fin, gold trim, burning "PsychoFlame" and midnight blue colour scheme makes the Banshee a sight to behold, making it far prettier than the relatively bland NX Edge Style Unicorn Gundam.
The Banshee also has more toys to play with, consisting of the Armed Armor BS and Armed Armor VN, each fully detachable from pegs in the arms where the beam sabers from the Unicorn can attach to. In addition, the Banshee comes with a beam effect part, which strangely doesn't connect anywhere and has to be supported by an additional stand. Nonetheless, it still looks great and gives you more bang for your buck.
If you only have enough cash to get one small Banshee, make it the NX Edge Style version!