First, the video where the guys are saying 1,2,3....go. That doesn't show anything because the 15 should have an edge.
When I took the tune out the car to take it back to dealer my car felt like it had dropped 2 cylinders..........and I can guaranty you the 15 would have put me 1 car behind it...........I guess it's not an apples to apples comparison.
Now with that said I have a 14 with CAI/SCT tuner and a can'd tune.
I just took a test drive in a 15 very similarly equipped to my car, mine has TrackPak, Brembo brakes, and Recaro seats, Tech, Sync with 6spd.
The 15 had the Performance Pak, Brembo brakes and Recaro's, Sync, Reverse Park Assist, and was a very nice Deep Impact Blue with the staggered 19 wheels....my 14 had standard 19x9's on all four with 255's on all 4. The 15 has 255's in the front on 19x9's and 275's on 19x9.5's in the rear. This particular car also had a line lock and Track Apps.
I bought my car used for less than $27k, it had 2700 miles on it and came with the Airaid CAI and SCT tuner.
They are asking $34,500 for the 15 and we could not come to agreement on what I wanted for my 14................so I had a nice test drive.
I think people had said this before so I will just briefly describe the feeling. My 14 just has a raw feeling, although the car has been lowered it still pretty much rides the same as it did stock and you can feel railroad tracks, irregularities in the road....etc.
The 15 felt more refined and not really raw, but it did feel good and especially corners.............it felt more planted and secure.
I really like the interior and prefer this over the 14. The shifter seems better, more solid than my 14. I love the staggered wheels and tires although the car still sits too high for my liking.
Although this motor has an advertised 15hp more than mine (mine has the CAI/tune) it just didn't seem to pull as hard as mine..........it would be interesting to put my 14 and the 15 in front a Christmas tree and see who crossed the finish line first, my guess is my car by at least 1 or 2 cars............but put a tune and CAI like mine on the 15 and you may have the reverse because the 15 doesn't spin the tires as much........the young salesman was a little surprised when I let the clutch out and put the pedal to the metal. and it did leave with a lot less spinning.
So, would I have driven home in the 15 if they would have given me what I wanted.......................probably.
Oh, my 14 is a base GT and so was the 15............but the line lock and track apps plus staggered tires/wheels along with color may have been the reason, she sure was pretty. My one concern is the IRS in the rear.......I'm not sure I'd want to be pushing the car hard as hard as I push mine on the Ford stock component rearend without some good axles/bearings and good adjustable shocks................Also lowering would be first on my list....IMHO