Anyone have a good argument to stay with a postpaid service provider rather than going to prepaid service?

Monthly, I feel more and more ripped off by Verizon. In all fairness, I have never been with another wireless carrier but the fees look about the same. I spend $165 for 700 minutes (we use about 100 on a good month), we text more than talking, have two lines of service, each have a data plan (mine is unlimited), and have been with Verizon for well over 13 years now. And all this is after a 17% corporate discount.

Tmobile offers unlimited everything for $50 a month for prepaid service. With two lines I would save $65 immediately.

If I want to upgrade my phone then I loose the unlimited data plan and I get to pay for the privilege of upgrading $30 for each line on top of phone costs.

Anyone have any good arguments for not going prepaid? Right now money talks. I refuse to pay an upgrade fee for someone to take 5 minutes to pull a phone, update it in the system and update contacts that will be done over the air anyway and signing for an early termination fee if I leave before the contract ends.