Track phones are for people who suck at keeping a job and can't just get a 2 year contract because they might be in jail next week and have to spend all their money on bail.
If you don't suck at life, get a contract, if you do suck at life, get a track phone.
By the way, there is no physical difference, just in the way you pay for it.
And sometimes track phones are the cheaper models.
But cell phones can also be prepaid, so i'm still not clear on the difference except that the track costs less. I don't plan on using it a lot
(but more than just emergencies) so $15 vs. $30 for Verizon seems to make sense on a tight budget....