Three iPad alternatives are impressive, but flawed

If you’re in the market for a tablet computer, why would you buy anything but an iPad? After testing three rival tablets, I’ve got the answer. You shouldn’t. Apple Inc.’s little marvel is still the king.

But keep reading to see how some creative engineers have developed a host of imperfect, but impressive iPad alternatives. LG Electronics has created the first tablet to combine 4G and 3-D technology. Research In Motion LLC, the BlackBerry people, have built a multitasking monster crippled by its limited software options. And Barnes & Noble is slowly transforming its Nook Color e-reader into a high-quality, low-cost tablet computer, by adding a library of popular software apps.

BlackBerry’s PlayBook tablet is the most frustrating of the bunch, and the best. Priced between $499 and $699, the PlayBook is laser-quick and blessed with the smartest user interface yet — better than the iPad’s.

It’s simply the best multitasking tablet ever. The border surrounding the PlayBook’s 7-inch screen is touch-sensitive. If you’re running its excellent Web browser and you want to switch to video, an upward swipe shrinks the browser and places it in a window on the upper half of the screen. This window shows all the apps you’re presently running. You can bounce from video to video game to online news, nearly as quick as thought.

Unless you plan on checking your e-mail or appointment calendar. The needed apps aren’t available yet. A feature called BlackBerry Bridge will connect a BlackBerry phone to the PlayBook, and transfer e-mail from phone to tablet. But iPhone owners are out of luck. BlackBerry says it will add the missing apps this summer.

The PlayBook’s unique operating system is also a major drawback. Since no other tablet runs this software, few developers will write apps for it. BlackBerry plans an upgrade that will let the PlayBook run apps written for Google Inc’s Android operating system, eventually. But for now, only hardcore BlackBerry phone users should even consider buying a PlayBook. Too bad; it’s a sweet piece of gear.

The new LG Electronics G-Slate isn’t quite as exciting, but not for lack of effort. Like the solid, attractive Xoom from Motorola Mobility Inc., the G-Slate features Honeycomb, the version of Android that is custom-built for tablets. But while the Xoom claimed to be the first tablet with 4G wireless data capability, the G-Slate actually delivers, sort of.

The G-Slate costs $529 after a $100 mail-in rebate, and with a two-year wireless data plan from its exclusive distributor, T-Mobile USA. That’s a decent price; the comparable 3G version of the iPad costs $200 more, and the Xoom is $70 more.

Besides, the G-Slate uses T-Mobile’s upgraded 3G service, which the company likes to call “4G.’’ In previous tests, I’ve gotten lousy results with T-Mobile 4G, but it’s getting better. The G-Slate delivered downloads at nearly four million bits per second, much better than standard 3G speed. The Motorola Xoom is supposed to get a free 4G upgrade later this year, but for now, the G-Slate is the best-performing tablet on cellular networks.

Of the G-Slate’s 3-D feature, the less said the better. It works, but you must view the videos through old-fashioned 3-D glasses with red and blue lenses, and the images are dull and discolored. It’s just a gimmick, but a harmless one.

As with the PlayBook, the G-Slate’s got a real software problem. Large-screen Android tablets have only been around for about three months, so it’s no surprise that there are few compelling apps to take advantage of all that real estate. Besides, most iPad users happily settle for the cheaper Wi-Fi-only version, rather than pay for 3G or 4G service. But there’s no Wi-Fi-only G-Slate.

Pricing isn’t a problem for the Barnes & Noble Nook Color. At $249, It’s one of the cheapest high-quality tablets out there; except it’s an e-book reader, and not a tablet, right? Well, maybe not. The bookseller has just launched a new app store for the device, with 130 apps to start with and promises of lots more to come. Yes, they include the beloved game Angry Birds.

B&N officials tell me they are going to be careful about which apps to offer. Expect lots of family-friendly games, along with software with bookworm appeal, like online news services.

The Nook Color is light on frills; no 3G or 3-D, not even a built-in camera. But it’s got Wi-Fi, smoothly runs a variant of Android software, carries a high-quality Web browser, and is beginning to get a respectable library of compatible software. It’s another promising iPad alternative. But few consumers will settle for tomorrow’s promises when they can buy an iPad today.