listen, brah. worth it down to the very last red cent.
the HR tracks your heart rate, brah. incredible stuff. back in my prime, before i started banking 250 Gs a year, i used a nike HR monitor for every run. it really helped me on my "easy" days to keep the run easy. maximized recovery, brah. it really did.
the pace tracker keeps track of your pace. again, good for tempos (in conjunction with a HR monitor) to keep a nice steady pace.
any self-respected runner has a nike watch. critical for every aspect of training, plus it makes you look good, too. all the ladies will say, "who is that brah with the fly watch on? that isn't nike, is it?" money in the bank every time!