As someone who has used both the XFPS Sniper 3.0 and XIM, I have to say the XIM is the superior of the two. Control is much more precise due to the XIM having customizable software which handles the translation of mouse movements into controller input. This is also why it can not be reliably reduced to a standalone unit, as without the software, you would be forced to use preset parameters (e.g. deadzone, X/Y-axis translation and sensitivity, smoothing, etc.) for translation which would result in no two games handling as well as possible.
A game like Battlefield: Bad Company has a larger deadzone than Call of Duty 4. With the XIM software, we can instruct the XIM to send only signals which will begin at the threshold required for cursor movement for each game. It essentially cuts out the deadzone that would normally be on the analog stick to avoid giving the mouse an unresponsive and loose control. If we remove that ability, you are forced to find a middle-ground between a small and large deadzone, which ends up making Call of Duty 4 receive signals that the analog stick is moving more than at least the minimum amount needed, while Battlefield will receive signals from small mouse movements that will not be of the intensity required to move the cursor or viewpoint controlled by the analog stick.
This is actually what the XFPS seems to do, and by requiring each game to use the same set of signals for deadzone, it does not allow many games with larger deadzones to be used with a mouse in any manner approaching playability. Though some of us can tough it out, it requires you be absolutely horrid with a controller and much better with a mouse to show any real benefits. The example I use is that of myself, of course. I was mainly a PC gamer prior to buying a console, primarily a CS:S player that held a 2+ kdr while having the occasional luck of landing in the area of 3-5 kdr.
With a controller in Halo 3, I might grab a .8 kdr. With the XFPS for a few games, I managed to end with a 2.56 kdr. Now, with more games and an XIM I have been swinging over and under a 2 kdr for the games I play, though how well I do still depends heavily on the people I play against (I can go from 4-9 to 16-5 between two games).
Enough useless type. Fileshare videos of Halo 3 with the XFPS and XIM are located at:
http://www.bungie.ne...r...ver of LulzUseless screenshots to back up CS:S claims:
http://rapidshare.co..._games.rar.html