I'm finicky about call quality. In fact, I've rarely lauded a phone's call quality--until now. In my hands-on experience, the navy-blue T-Mobile Wing ($300 with a two-year contract) sounded terrific. While on calls, I heard virtually none of the tell-tale hissing or background noise that usually betrays the fact that I'm on a cell phone. And the people I spoke with noted that I sounded very clear --even while on a noisy jetway at an airport. Call quality isn't the Wing's only strength: It also offers impressive battery life and a strong array of features.

The phone--the first to ship preloaded with Windows Mobile 6.0 (T-Mobile is also making Windows Mobile 6 available as an upgrade for the Dash)--has many features, including a still-image and video camera, messaging, and the familiar Windows-like menu system with apps to go. The phone includes Office Mobile with Word, Excel, and PowerPoint (you can view, create, and edit documents); Windows Live for Windows Mobile (with Windows Live Messenger, Windows Live Hotmail, Live Search, and Live Spaces); Windows Media Player; and a My Documents folder structure for storing files and multimedia. Other apps include Instant Messaging (for use with AOL, ICQ, and Yahoo), Java applications, a T-Mobile HotSpot log-in shortcut, and a voice recorder.

The Wing comes with a 2.8-inch touch-screen display (T-Mobile bundles a stylus with the phone, but I tended to rely on my fingers to do the walking). Six highly responsive buttons, and a five-way navigational control beneath the front-screen display make single-handed navigation a breeze. Slide the display left, and the screen automatically reorients itself in landscape view to accompany your typing on the roomy keyboard. The keyboard's keys are wide and flat, with backlighting that makes using the device in a darkened environment a breeze. I found the Wing surprisingly comfortable for thumb-typing when I held the device in two hands; as a touch typist, I was surprised at how quickly I could type (I have small hands; a friend with larger hands found the keyboard harder to navigate).

Unfortunately, other aspects of the phone's design are less appealing. Specifically, I found many of the buttons around the perimeter of the phone difficult to press and poorly constructed. For example, the volume slider, located near the middle of the phone, along the left-hand side, was difficult to adjust using the pad of my finger (if you have longish nails, this might not be an issue).

The dedicated camera button is located near the top left of the camera when the phone is oriented vertically, and at the top right when the phone is situated horizontally--the optimal way to use the camera. But the button is flat and hard to press. When I did click it, I often accidentally twisted the phone's slider mechanism, too, which makes me worry about the long-term integrity of this critical part of the phone. Pressing the camera button launched the phone's 2-megapixel CMOS digital camera, with its 8X digital zoom (for low-resolution images) and video camera (capable of capturing clips at up to 176 by 174 resolution), but the phone lagged considerably while the camera popped up.

I suspect that some of my gripes with the phone may relate more to Windows Mobile 6 than to the device itself. The Communications Manager app, for example, houses a dizzying array of options--everything from vibrate and ringer settings to EDGE and GPRS data-connection minutiae. To disable the wireless antennas and put the phone into flight mode, I had to traverse three screens--more before I found a helpful shortcut--just to get to the point in Communications Manager where I could disable the wireless radio.

Like the T-Mobile MDA, the Wing (underlying model number HERA110) is manufactured and designed for T-Mobile by HTC. T-Mobile claims that the Wing is about 30 percent smaller than the MDA. It certainly feels more compact than the MDA, weighing in at 6 ounces and measuring 2.3 by 4.3 by 0.7 inches. When closed, the Wing is dominated by its 240-by-320-resolution, 65,000-color touch-screen display. When open, it suggests a sleeker version of T-Mobile's Sidekick III.

The Wing is a quad-band GSM phone, with support for 850-, 900-, 1800-, and 1900- MHz bands. It runs a 201-MHz OMAP850 processor, with 64MB of RAM and 128MB of read-only memory. According to T-Mobile, the phone by default comes with 26MB of free memory and 16MB of available program storage. You can add storage for multimedia and data files via the MicroSD card slot.

The Wing lasted for the full 10 hours that marks the ceiling of the PC World Test Center's battery life evaluation. Its performance thus matches that of such models as the T-Mobile MDA (which this model replaces) and the RIM BlackBerry Curve 8300--our most recently tested top performers.

The phone comes with a case and an assortment of cables and connectors. The 258-page manual covers all of the important topics; regrettably, T-Mobile doesn't include a copy of the manual on the phone itself in PDF form so that you could view it on the loaded Adobe Acrobat LE reader. When I sought assistance within the phone, the included Microsoft help file didn't address my needs.

For $300, the T-Mobile Wing is a reasonable value, given the phone's versatile functionality, stellar call quality, and excellent battery life. My greatest concerns about the phone involve its limited on-board storage and its poorly constructed buttons; longer term, Ia??d worry about the integrity of that slider mechanism. But those concerns aside, the Wing makes a great package, especially if you value the easy input that a touch screen affords, together with the computing flexibility of Windows Mobile.

-- Melissa J. Perenson