the field between P5 and non-P5. Also, I'm assuming Utah government would've upped the tax subsidy to try to keep pace a bit, so ultimately Utah residents pay more in taxes, but the school revenues stay about the same to what they are now (except better for BYU).
On field performance is difficult to estimate, but BYU would be in a better position obviously than being independent. Probably fewer bowls but higher rankings in computer-based rankings due to improved SOS.