Why not. I've no problem with that. I looked at hoods and vents over the past 2 years and always come back to liking my hood and not being able to find a suitable set of vents. The 2015 vents are exactly what I'm looking for although I'm not sure they're narrow enough for the creases in my hood.
I assume you mean the BMC-421869. I just sent Roush a note asking if they'll fit a 2011 GT hood and what the dimensions are. I thought I read somewhere that someone thought the Roush ABS ones looked cheaper than the stock ones although I imagine the ABS would mold better to a hood.