With the number of features I-mate has crammed into the K-JAM (including the very useful keyboard), you'd expect this device to be on the larger side, much like the O2 series. Not so. We were pleasantly surprised when we first held the K-JAM. It's not small and svelte like the JAMin or O2 Atom, but it isn't terribly large either. In fact, the K-JAM is almost perfectly shaped, but rather thick due to the keyboard. You can fit it in a pocket, but at 160 grams, you will feel a noticeable weight, though we soon enough got used to this.

In our opinion, the K-JAM strikes a neat balance between the excessively large JASJAR (which will be too large for most) and the tiny sized JAMin, (which perhaps isn't as suited to PDA functionality).

The K-JAM features a 320 x 240 resolution display, the screen is bright and clear and at only 2.8" diameter the pixel density is very high, so high that clear-type does not make a great deal of difference. One interesting thing to note is that the QTEK 9100 offers clear-type but the K-JAM has the clear-type function disabled, it's visible on the screen setting but is grayed out, perhaps a feature we'll have in a later ROM release. We compared the screen of the K-JAM to the QTEK, some observers have noted a difference in quality, we were unable to tell any difference in low light, high light, inside and outside, I suspect that the origins of both being the HTC Wizard that they are in fact identical.

There is a camera built in (1.3 megapixels), yes it has a flash unit, and yes there are other extras like voice control for applications, voice dialling, a PDF reader and the usual Windows Mobile fare like Internet Explorer, SMS, MMS and e-mail, and diary management.

The removable battery is the same size as the previous JAM, battery life is predicted to be between 3.5 and 5 hours of talk time with a standby time of between 150 and 200 hours. These figures are approximate, there are so many options and variables such as which radios are switched on whether the user is browsing the Internet and hence using the backlight whether it is a single call, many calls or whether the unit is moving through cellular towers that predictions on battery life really have to be made in the context of daily use, basically, will I need to charge it in the middle of the day or will it do what I need throughout the day? The brought answer to that is yes, in a typical usage scenario where we'll see perhaps an hour of calls in and out, an hour of travel, perhaps 30 minutes of web browsing and a day's worth of email sync. over GPRS the K-JAM ends the day with at least 25% of its battery intact, reduce the use of Wi-Fi and more than 50% is left.

Music playback was good, the supplied headphones are of typical supplied headphone quality, fairly poor but do include a microphone in the line so in the absence of a good Bluetooth headset you can still use the K-JAM in your car with safety. Plugging into a good set of headphones the quality was great, plenty of depth, good bass and a modest treble. The audio quality was easily the equal of an Apple Video iPod.

In the memory stakes, the K-JAM is outfitted with 64MB RAM and 128 MB ROM, of which 47MB is available for storing your data. This is fairly standard, as is the non volatile memory on Windows Mobile devices, meaning the unit won't wipe your data if reset. The most disappointing aspect of the memory for us is the fact that the K-JAM takes mini-SD cards, not the more common SD. We say disappointing because we, like many people no doubt, have a few SD cards lying around and would have to buy a miniSD just to use with this device, an extra expense you will have to factor into your purchasing decision.

Bluetooth

Bluetooth support on the K-JAM is much improved over the previous model; Microsoft having improved Bluetooth in Windows Mobile 5. I was able to pair with a number of headsets from Motorola, Bluespoon, Logitech and my Mini Cooper. In all cases calls were handled correctly and audio quality was at the best each device could support. The Bluetooth support also extends to OBEX transfer and support for human interface devices. I was very pleased when I was able to quickly pair my Bluetooth keyboard with the K-JAM and start typing straightaway. Access to external keyboards takes the K-JAM to the next level of usability; I was able to type on a full sized keyboard at full speed.

The Bluetooth radio electronics did not appear to impact battery life; it's hard to tell as the functionality is so useful you would be unlikely to switch it off. I would consider the runtime of the unit to be measured with the Bluetooth radio turned on.

WiFi

The K-JAM supports 802.11b, Wi-Fi. The Wi-Fi is switched on and off from the included communications manager, which in turn is activated by a dedicated button on the K-JAM. Performance on Wi-Fi was very satisfying; security was good supporting WEP, WPA and LEAP standards. The interface on the Wi-Fi side is fairly basic, but functional. There are no elaborate utilities for performing a site survey. I was easily able to add home and office Wi-Fi settings and was able to reliably connect, and stay connected which is what you need.

Compared to Bluetooth Wi-Fi requires much more power, to that end the Wi-Fi controls in the communications manager allow more detailed settings for Wi-Fi power management. However, if you are driving in your car and passing Wi-Fi network after Wi-Fi network the radio never switches off and instead use is all the power it can muster to attach to any network it can, the result is a big battery drain. Given that the GPRS edge network is more than suitable for e-mail I would recommend leaving the Wi-Fi radio switched off unless absolutely needed

Games run well though it does not appear to have a dedicated graphics processor, they always use too much battery power anyway! The display and the new joystick lend the unit to a bit of gaming; not a strong point for me, my favorite games are e-mail calendar and contacts!