I have the MRT louvers and I have seen the Roush car when it was at Summit Racing this past summer and I personally prefer the MRT's due to the more streamlined appearance. The Roush don't look bad but they stick out more and the fins are a little too large for my tastes.

 

I have the MRT louvers as well. The thing that still upsets me is MRT has yet to release the proper mounting hardware so we can remove the louvers to clean the windows. I have been waiting since May for the brackets and still no word as to when they will be ready, if at all. Looking at MRT's site they are now saying that the louvers are just taped onto the body so I have a feeling they have abandoned the bracket. Pretty disappointing since I was expecting this feature, but then again, I'll probably never remove them and still love the looks of them.