Reminds me when someone asks which computer to buy ... a Mac or a PC.
the TI is much like the PC ... large user base, lots of support available.
HP is kinda like the Mac ... hardcore users swear by them, but the user base is relatively small.
I still have an HP-35 scientific that I am very comfortable with and use it for most everything that doesn't require a graph.
Both are good calculators ... pick one and run with it.