So, after much anticipation, Apple (AAPL 0.10%) rolled out its iPhone 5S and iPhone 5C. The tech giant's latest flagship smartphone is available on all four national carriers Verizon (VZ 1.50%), AT&T (T 1.54%), Sprint (S)and T-Mobile (TMUS -0.77%), but which iPhone carrier is best?

Each carrier has its strength, weaknesses and something unique that differentiates it from the rest. Let's check out in detail the carrier that best suits your needs.

Picking the best iPhone carrier

The largest US telecom provider, Verizon offers the 16GB iPhone 5S for $199 with a two-year contract or monthly payments of $27.15 for a couple of years for the early upgrade program, Edge, which allows you to upgrade your phone every six months. Users can get unlimited talk time, texting and 4GB data plan for $110 a month, which is less attractive than a similar AT&T plan. For the same price, the second largest US carrier offers unlimited talk and text with 5GB data usage with mobile hotspot service.

The Dallas-based carrier is offering iPhone 5S for $199 with a two-year contract. You can also opt for AT&T's Next, through which you can have the 16GB iPhone by paying $27 a month installments for 20 months, $32 for 32GB, and $37 for 64GB. Additionally, the Next allows users to upgrade their phones every year.

On the other hand, the third largest carrier, Sprint, has made an aggressive strategy to attract iPhone buyers from other carriers. The carrier has proposed to cut down $100 on the upfront cost of purchasing the iPhone if a customer of a rival ports the number to Sprint's network. Sprint would offer the iPhone 5C without a down payment to such customers, while charge them $99.99 for 16GB iPhone 5S with the two-year contract.

T-Mobile is also making an offer similar to Sprint's. Buyers can get the 5C without any upfront cost, while the 5S would come for a cost of $99.99. However, this comes with a condition that the buyers would have to pay for the unsubsidized price of the smartphone in monthly installments for two years. In contrast, Verizon and AT&T are charging $99.99 and $199.99 for iPhone 5C and iPhone 5S, respectively. In such case, Sprint's deal looks more attractive.

Also, Sprint has launched an early upgrade program called One Up. The Kansas carrier is also attractive as it is the sole telecom player that truly offers unlimited data usage plans. For $110 a month, the mobile carrier gives unlimited talk, text, and data along with 5GB a month hotspot. Now that Sprint's plan appears the best, it is all nullified by its inefficient 3G service. Its 4G LTE service is yet to mature, and unless people are covered under its 4G network, they will not be able to enjoy the unlimited data plans.

Verizon's LTE moat

When it comes to the 4G LTE coverage, Verizon stands as the unmatched leader, covering over 300 million Americans in 506 markets. In comparison, AT&T's 4G LTE network spans 397 markets, but is known for its speed that outperforms Verizon's network speed, particularly in New York City. The largest carrier is working on doubling its speed through its new Advanced Wireless Service, or AWS. However, it's not known if the latest iPhones are AWS-enabled, which supports such upgrading.

In comparison to the big two, Sprint and T-Mobile are way behind. Sprint has robust plans to boost its LTE expansion. Presently, the company's 4G LTE spans over 151 markets. The carrier is not giving 4G LTE service in major places, which is a huge drawback. T-Mobile, on the other hand, has LTE coverage in 116 markets only.

My takeaway

Undoubtedly, T-Mobile is providing one of the most interesting pricing packages with unlimited talk, text and data for $70 a month and without binding buyers in any contract. This can be done through buying the iPhone outright or entering into an installment for 24 months after making a down payment. Despite such an attractive offer, I wouldn't suggest anyone go for it as the carrier's LTE coverage is the poorest of all the national players. By the time its coverage gets any better, it would be time for the next iPhone release. Using the same logic of 4G LTE coverage, you can eliminate Sprint as well.

Enjoying a premium handset such as the iPhone to the fullest is not just about selecting a carrier's plan, it's more about choosing a carrier with broad coverage and good data speed. T-Mobile or Sprint should not be considered as the iPhone carrier this season. This means there is a close call between the Big Red and the Dallas giant.

Which iPhone carrier to choose? This depends a lot on the requirement of the user. Picking between Verizon and AT&T is like choosing between coverage and speed. People looking for greater coverage under 4G LTE would prefer Verizon, while those looking for speed would support AT&T.

However, the second largest US telecom player boasts of providing the best Internet speed to its subscribers. It is the only US carrier that offers 4G network both on LTE and HSPA+ technology. The carrier's 4G service for smartphones is considered as a benchmark for the industry. AT&T's coverage is slightly behind Verizon and it won't take long for the carrier to catch up with its larger rival. I believe AT&T would suit an iPhone user's need the best. What do you say?