Replying to __Do boots make you a better skier?__

Hey guys I was just wondering if boots actually make you a better skier like on rails and with flipping and stuff. I've had these same Nordica seasonal rentals for like 3 years now because I don't want to drop $300-400 on a new good boot until my feet stop growing. Do you like your boots tight when you ski or looser? Also other than full tilts what boots do you think would be the best for park? Dalbello, Atomic? I'm just wondering if my boots are somewhat keeping me back from my full potential?