What has your been experience been with graphing calculators?

I’m still in high school and I have a TI-84 Plus C Silver Edition, and for my AP Calc BC class I’m finding that it’s sub-par when compared with the calculators of my peers. I feel like a TI-89 or an HP Prime would help out a lot, and they’re allowed on the AP exam, but I want to know whether I need an 89 or a Prime for college (going to Computer Science major). Are these powerful graphing calculators allowed in college math courses? Thanks!