The newest Motorola Droid is RAZR-thin and lightning fast—but it’s a handful, at 5.2 inches high and 2.7 inches wide.

Motorola's newest Droid has a moniker that five years ago belonged to the most coveted flip-phone line of phones in the world. The RAZRs of old were renowned for their sleek appearance and fast hardware. The new Motorola Droid RAZR, which went on sale today at Verizon stores and retailers for $300 with a two-year contract, can make the same claims.

The new RAZR is an Android smart phone that squeezes a brilliant, 4.3-inch Super AMOLED display, an ultra-fast dual-core 1.2GHz CPU, an 8-megapixel camera that can capture video at 1080P, and access to Verizon's super-fast 4G LTE network into a case that's just 0.3 inches thick (the top quarter-inch of the phone that houses the front and rear cameras is actually 0.4 inches).

In using a press sample of the phone, I found the phone a tad uncomfortable to hold: After a while, the sharp edges of the Kevlar-fiber case started to dig into my palm. I also found it too easy to accidentally press the power button, which rests just above the volume rocker switch on the phone's right side. But these are just minor quibbles, compared to the phone's advantages.

The details:

It's fast. As with its sibling, the Droid Bionic, the RAZR’s applications blinked right on, and Web-based content filled the phone's screen in a fraction of a second. One difference: The phone's 1,780-mAh battery seemed to hold up much better than the one on my Droid Bionic press sample. The RAZR’s battery gauge barely dropped as I checked multiple e-mail and social network accounts and streamed movies and music on Verizon's 4G LTE network.

It's brilliant. The Droid RAZR's display seems just as dazzling and just a smidgen sharper than our current display stars, the Samsung Galaxy S IIs. Small type was clear and sharp on the phone's 960-x-540-pixel screen. Consumer Reports engineers will put the retail version of the RAZR through its paces in our labs and report more specifically on the phone’s display quality.

It's smart. The RAZR comes with several free features intended to improve productivity, enhance entertainment, and even lengthen battery life. One, called Smart Actions, lets you program the phone to change its settings according to your GPS location or battery level. For example, you can set it to turn on Wi-Fi and shut off Bluetooth when you arrive at home or work. Or you can have the phone turn screen brightness down when the battery level gets below a certain point. I'm not sure how much battery life these routines save, but I do appreciate the option to use them.

Another feature, called MotoCast, is a rebranded and beefed-up version of Zumocast. This free service lets you download or stream multimedia, Office documents, and other files from up to five computers (PC and Mac) to the phone over the Verizon network. In short, your computers become content servers for the phone.

As with ZumoCast on the Droid Bionic I reviewed a few weeks ago, MotoCast let me access Office documents and my iTunes playlists. And the interface includes the TuneWiki service, which shows you a song's lyrics as it plays and suggests songs from similar artists you can buy from Verizon's V-Cast service, which is not free.

But MotoCast wouldn't let me stream copy-protected videos from my computer. What's more, streaming videos seemed to put a lot of stress on my late-model PC. When I launched a video to stream, the PC's hard drive and fans whirred like a jet about to take off. Streaming music and downloading files, on the other hand, seemed to have little impact on my computer.

What concerned me most about MotoCast, however, is the software you need to download to your PC in order to use the service. It disables your computer's sleep mode, leaving it on all day. That's hard on your computer, and could also be hard on your electric bill.

It's tough. The RAZR's Kevlar fiber case and Gorilla Glass display was more than able to survive my torture test, which included throwing the phone across the room, banging it with a hammer, and letting a violence-prone coworker stomp on it. The phone was even able to survive a collision with a subway train—albeit the toy kind (see video below). But it's not waterproof, just "splash-resistant," according to Motorola, so my aquarium fish were relieved of testing duty.

Bottom line: The Droid RAZR offers an excellent blend of speed, sleekness, and smarts, but it could use softer edges. Check back with us soon for the results of our lab tests of this highly promising phone.