Having had both a 2005 GT and now a 2013 GT / CS, I can say that the newer cars are much better in just about every way. Just from a stock vehicle standpoint, the interior is worlds better, and the 5.0 is a night and day difference over the 4.6, so much so that it required a little mental recalibration on my part. It's not just faster, it's a completely different animal. Both Roush and Saleen offer fantastic upgrades, but in the end the 2012 is going to be faster, handle better, and be a much better car, regardless of price. It's just the evolution of the model. So like everyone else, I would say the Roush, hands down.