The FS version is very stiff making the suspension work more. Depending on the carpet and tires then the stiffer chassis may help or not. I haven't had me E4 LE on carpet yet but plan to within the next month or so and then I find out. (The 2.5 E4 chassis is very stiff as far as I'm concerned.)

My guess from how it handles on asphalt is that it will be fine on carpet as well but will need a stiffer suspension set up and lower ride height.