Carriers sometimes offer the same makes and models, often for the same prices. Apple's first and so far only LTE model, iPhone 5, is one example. Samsung LTE smartphones are another, including the latest Galaxy S III and Galaxy Note II. Some models are exclusive to one carrier, or offered by a subset of them.
Each carrier has a core offering, sometimes a small core, based on one or two smartphone vendors, then a sprinkling of other brands. T-Mobile's high-end 4G offerings are packed almost exclusively with Samsung models. Verizon Wireless offers at least four Motorola Droid Razr models. AT&T features a trio of HTC models.
Less expensive LTE phones fall into two groups. One group is phones designed to be less expensive, with somewhat less powerful processors, lower resolution displays, lower-end cameras, possibly less internal storage, and plastic instead of metal bodies, for example. The second group is somewhat older models, released six to 12 months or more earlier. At the time of release, they may have been top-of-the-line, and often top-ranking, phones that now are being marked down. These include the older Samsung Galaxy S II, the Galaxy Note and several Motorola Droid Razr models.
To evaluate the current offerings, we visited each of the Big Three LTE mobile carriers' websites and looked at customer ratings. The websites vary in their details but generally let you see the total number of reviews, the overall score (usually broken in several subcategories) for the phone, usually the percentage of customers who recommend the model, and of course their comments. Comments can range from brief summaries like "nice phone, no problems so far" to highly detailed evaluations that include a breakdown of different features or qualities.
Some recently released phones have only a handful of reviews. We decided to list only those that, at the time we prepared the list, had at least 20 user reviews. If the new phones prove popular that number will quickly increase, so be sure to check the carrier's smartphone pages. You can usually filter your search results, for example, selecting "LTE" (or "4G" or "4G/LTE"). CAUTION: there's no formal definition for "4G" and carriers offer HSPA+ phones, which can deliver very good download speeds as tests of T-Mobile's network have shown. If you want an LTE phone, check the product page to confirm "LTE" is listed.