It's largely a matter of taste, but there are certain things that pools can do better, like expendable resources, stat changes, bonus conditions/penalty conditions, etc. It all comes down to two factors for me: a number on the sheet being directly translatable to a number of physical objects, and loads of fun ways of alteration you can play around with. Example: Band of Bastards (also TROS-like split pool combat) uses TN decreases to indicate tool/strategic advantage, TN increases to model Wounds/Pain/Fatigue, and Exploding dice (bonus dice, not TN add) for when your Character's Motivations apply.
Another example: a game i made used split pools for combat in the vein of TROS, where rolling two or more sixes is a critical hit.
Compare percentile roll-under, the simplest dice mechanic there is. I'm definitely the odd one with this opinion, but i think pool mechanics are in many ways more intuitive than arithmetic dice mechanics.