T-Mobile’s Samsung Galaxy S bests other recent smartphone releases. (Oliver Bunic/BLOOMBERG)

You could call 4G the flavor of the month in smartphones, but that wouldn’t be right: With the four nationwide carriers serving up different forms of fourth-generation wireless broadband, there is no one flavor.

Depending on your choice of AT&T, Sprint, T-Mobile or Verizon Wireless and their coverage near you, 4G can mean a massive speedup from 3G, an incremental but still impressive upgrade or no benefit at all.

4G speed can also bring costs of its own, as seen in a test of four new smartphones running Google’s Android software: AT&T’s HTC Inspire 4G, $99.99; Sprint’s HTC Evo Shift 4G, $249.99 before a $100 mail-in rebate; T-Mobile’s Samsung Galaxy S 4G, $249.99 before a $50 mail-in rebate; and Verizon Wireless’s HTC ThunderBolt, $249.99.

All those prices require a minimum bundle of voice and data service: $54.99 on AT&T, $79.99 on Sprint, $49.99 on T-Mobile and $69.98 at Verizon. Adding an allotment of at least 500 texts (Sprint includes unlimited texting) and upping the unrealistically low data quotas of the AT&T and T-Mobile plans pushes the monthly cost to $79.99 at T-Mobile and about $75 at AT&T and Verizon.

In terms of speed, you can categorize those four as the ThunderBolt and everything else. Verizon’s 4G LTE (Long Term Evolution) network gives this phone the kind of speed usually confined to cable or Verizon’s Fios fiber-optic service: more than 10 million bits per second (Mbps) downloads, as clocked by Speedtest.net’s app, and uploads even faster at an unreal average of some 30 Mbps.

The ThunderBolt paid for that speed, however, with woeful battery life. Just leaving it idle on a desk for 24 hours drained two-fifths of its battery.

Sprint’s Evo Shift, using that carrier’s WiMax 4G service, averaged 5.5 Mbps downloads and 1 Mbps uploads. AT&T’s Inspire and T-Mobile’s Galaxy each run on an upgraded version of 3G called HSPA+ and yielded varying results: 1.6 Mbps downloads and 0.2 Mbps uploads for the former, 4.5 Mbps and 1.6 Mbps for the latter.

Those phones also could last longer away from an outlet. The Sprint Evo Shift lost more than a third of a charge in 24 hours of idleness, but it also lets you shut off 4G service to extend that time. And AT&T’s Inspire and T-Mobile’s Galaxy only lost a bit more than a tenth of a charge in that standby test.

Battery concerns should weigh heavier than 4G speeds in practice, because you might not notice the faster downloads on each phone’s screen — 4.3 inches for the Verizon and AT&T phones, 4 inches on T-Mobile’s, 3.6 inches on Sprint’s. Few files or streams you’d view on a phone require that kind of bandwidth.

(The Shift might have the smallest screen, but its slide-out keyboard makes it the thickest phone of the bunch, about five-eighths of an inch.)

To make real use of 4G, you need to add tethering, the ability to share your phone’s bandwidth with a nearby device. And that costs extra: $14.99 a month at T-Mobile, $20 at AT&T (on top of its required $25, 2GB Data Pro option) and Verizon, and $29.99 at Sprint.

AT&T, Sprint and Verizon employ the same, simple Mobile Hotspot app to set up tethering (and even default to the same insecure password). Sprint and AT&T allow connections to only two devices, while Verizon accepts up to five. T-Mobile buries this option in the Settings app and allows up to five connections.

Software is a weak point on all the devices. They all run the 2.2 version of Android that Google debuted in May. Its replacement, Android 2.3, has been out since December and provides better battery life and text editing, among other things.

None of these carriers could resist the temptation to lard up Google’s software with a grab-bag of third-party apps: game demos, proprietary music and movie players, and navigation tools. Worse yet, you can’t uninstall most of this junk without warranty-voiding tinkering.

Verizon “wins” this competition — the ThunderBolt is almost as encrusted with junkware as last year’s woeful Samsung Fascinate. T-Mobile deserves credit for the bizarre marketing decision to load a copy of the movie “Inception” on the phone.

At the same time, Verizon and T-Mobile neglected to include a widely used video-calling app for the front cameras on their phones; T-Mobile includes Qik, while Verizon, having delayed its plans to bundle a version of Skype, has nothing.

All four phones tout high-resolution cameras on the back, but the 8-megapixel units on the ThunderBolt and the Inspire and the Galaxy’s 5 MP camera took notably better shots than the 5 MP Shift.

Factoring in all those things, T-Mobile’s Galaxy S looks to be the best of this month’s class. The ThunderBolt’s speed might be astounding, but so is its ability to chew through batteries. If you can deal with its less-generous coverage, it’s hard to beat T-Mobile’s pricing, both for entry-level service and for add-ons such as tethering.

But you won’t have that option if AT&T carries out its plan to buy T-Mobile. Enjoy your choice while it lasts.