The biggest problem with these claims are the intangibles. If we were just talking about voice calling, this would be an easy comparison. That's because voice plans are simple to figure out. It doesn't matter how many minutes you need. You will be paying and getting an Unlimited voice minute plan, whether you need it or not. There is no money in voice minute plans these days. It's all about data and that is where things get murky and comparisons must end. Here's why...
1) Throttling versus data overage fees Some carriers slow you down. Your e-mail and social networking still works, but watching video or using voIP becomes difficult until your next billing cycle. The alternative is to choose to pay for more 4G data until your next billing cycle. I'd prefer the choice, versus losing all data capabilities until my new billing cycle.
2) Data Rollover (Some carriers like AT&T roll it for a month. T-Mobile rolls it until the end of the year. Verizon is rumored to be talking about doing something similar to AT&T with the one month of carry over data. Ironically, it was Cingular (AT&T's new parent) that introduced voice minute rollover. They initially rolled minutes over yearly until December 31st. It appears they are not as generous with data as is T-Mobile. You cannot compare rollover data when some carriers only roll over one month and others rollover data for the whole year.
3) Global Texting and Data Costs. Some carriers, like T-Mobile, offer free text and data in over 140 countries. Others charge for it and/or offer "bolt-on" plans that discount the normal costs while roaming.
4) Streaming Data also cannot be compared. Costs and data speeds vary too dramatically between carriers. Example... T-Mobile offers free music and video streaming without even counting against its 4G allocation on many plans. T-Mobile does not charge extra to use your SmartPhone as a HotSpot as long as you have enough 4G data on your plan to support this feature.
5) T-Mobile only charges $0.20 per minute for voice roaming in over 140 countries. Anyone who travels regularly will find this to be an amazing value as other carriers charge as high as $5.99 per minute.
There are rumors that Verizon is going to increase the costs of their data plans and the amount of data they offer. There are also rumors that the biggest plans may get throttling and data carryover for a month. I will update this story when that happens...