I got the K-Jam and am very happy with it. JasJar is too big for me, and it's only selling point being the VGA screen - leaves much to be desired in the clarity department... The other Imate products lack the keyboard - so the K-Jam fitted my requirements.
Straight out the box it "appears" to be slow ... however with much needed "tweaks" to the OS, etc it runs like lightening (It is a dual core process after all).
When choosing a device like this bear in mind that because of the nature of the device (Being a Pocket PC) and depending on how often you load / remove software from the device as well as what software, might entail you to "rebuild" it - like you would with your laptop / desktop over time. It is running a microsoft OS after all.
The capabilities of this device are endless, and IMO nothing comes close in terms of features, abilities, etc.
But at the end of the day it all comes down to what you want out of a device like this...
Regarding the closing of the apps, Microsoft again left out a task management app in Windows Mobile 5, as pressing the "X" on any native pocket PC device normally minimises the application... but as Azrael pointed out there are many applications that get around this problem, I use Pocket Plus, which enables me to close / minimise apps.
