-For most people unlimited data saves them money under 4 GB of usage.
-An exception to this is if your plan is already over $100 before unlimited data. Then you are probably spending more keeping unlimited data.
-All of Verizon's new plans with data require the plan fee in addition to the access fee.
-Verizon's basic plans cannot be used with with smartphones. They are for basic phones.
-To summarize: Unlimited data is worth keeping if you:
Think you're going to use it in the future. (Even though it might not be around.)
Use it now. (The amount you pay/use is equal or less than the corresponding GB amount under the Share Everything plans.)
Can deal with saving the money you save keeping your unlimited for your off-contact device.