If this will be the last mod for your car, or you don't plan any extensive modifications, then I believe that this will still provide a noticeable improvement for you. The UIM is one of the greater restrictions in the intake path (probably the greatest, short of the stock air box), so upgrading it in this fashion makes sense, mon ami.
Now, if you are planning on doing other future modifictions, like ever getting headers, and an SVT TB, then I would absolutely JUMP on this. You don't want to be stuck with a crappy lo-flo intake as the major restriction to power in your otherwise hi-flowing system. Thus, if you're upgrading the air-path in the future (and be honest with yourself about whether you will do this or not), it makes total sense to do the UIM now. Especially from a cost vs. opportunity perspective.
