When in doubt..flip a coin for it
I do not think a Hero is really a worth while upgrade from a TP2 and you can play with android on a TP2 on your off hours..its not fully complete but good enough to play with.
For me the TP2 is speedy and I haven't done a reset in a LONG time...running smooth too..but if you feel like you really need to switch Sprint has the 30 day trial thing you can take advantage of.
What rom are you using by the way?