Sprint's upgrade plan is official: One Up lets you upgrade annually

As predicted, US wireless service Sprint rolled out a new upgrade plan for customers just in time for the release of the iPhone 5c and 5s. Called One Up, Sprint's plan gives the company an alternative to similar programs offered by competitors Verizon, AT&T and T-Mobile. Is it worth the money? Let's take a look.

Under the One Up plan, you buy an eligible smartphone (or tablet, including the iPad) and agree to pay for it in 24 monthly installments - subject to credit approval (which affects the finance rate at which you can get the device). After 12 months, you're eligible to upgrade to a new device once you trade in your old one. One Up is also available to some Sprint customers if they meet eligibility requirements (including those who have had their current phone for 12 months).

Sprint is making an aggressive play to woo customers away from Verizon and AT&T by offering inexpensive unlimited service plans and a guarantee of unlimited talk, text and data for the lifetime of the service. There are a couple of provisos to Sprint's claim of unlimited data, however: Sprint limits streaming video speeds to 1 Mbps, and reserves the right to offer "prioritized bandwidth" to other plans.

Sprint's "Unlimited, My Way" plan is normally priced at $80, but enrolling in One Up makes you eligible for an "introductory" rate of $65, so the company's offering some savings to customers who take advantage of the upgrade program.

For subscribers, Sprint is squarely in third place behind Verizon Wireless and AT&T. With about 55 million customers, Sprint has about half the customer base of AT&T, though it's squarely ahead of T-Mobile.

In the end, Sprint's upgrade plan can make it easier for you to get a new phone every year, and an annual program is probably the best sort of plan to be on if you're an iPhone user, since Apple pretty much sticks to a new phone model every year.

I'm a big believer in paying for phones off-contract, but getting a good value from doing so requires you to avoid paying a carrier subsidy. AT&T and Verizon do that even if you participate in one of their upgrade programs, which makes those programs a complete waste of money. So Sprint and T-Mobile both offer attractive alternatives - both offer fairly inexpensive plans, especially when you get into a shared plan between multiple family members.

Years ago Sprint bet on the wrong pony in the race for next-generation high-speed cell data networking: Wimax. Now it's playing catch up as it builds out a 4G LTE network, but it's woefully behind Verizon and AT&T. Anecdotally, Sprint customers who complain on social networks and forums like ours usually point to Sprint's inadequate coverage as the major issue. Sprint's network upgrade is in overdrive, and they've made significant progress: they anticipate having 4G LTE coverage for 200 million people in the U.S. by the end of the year. That improved coverage, combined with an easy way to afford expensive new smartphones, may drive customers their way.