I rooted my G2 *shrugs* how else was I going to get HTC Sense 2.2 on here?!?!
But anyhoo... for me, the biggest thing with root was the OC kernel governor... Now I can have my phone running at 245 mhz when the screen is off to save me energy (which has improved my batt life a lot)
If you root... you root. If you don't... you don't. Plain and simple.