Ford is giving 0% financing on the 2015's until Sept 8th, (apparently even to barely prime FICO's, the finance mgr should be able to tell you upfront, better yet, just apply online. You should get at least $3K off msrp, plus with all the interest I saved, I paid $1600. for the 6 year/100K extended Ford Warranty (again, thrown in at 0%)!
I would wait for the 2016 I would also rethink the V6 purchase. I have heard that with the right tuning kit you can get nearly 500HP out of the Ecoboost motor. Granted I do not know whether or not those tunes void the warranty (I'd imagine so).
The current sync system in my '13 has been the only reason to return my car to the dealer since buying it. It has shortcomings. I cannot send a voice text message on an apple device, yet I can receive them - what were they thinking? I still have an unresolved issue with my iPod where sync will not play the requested song, in spite of repeating the title back to me correctly.
2013 GT Premium Brembo
MGW, Blow Fish, AM Hood Struts
Tinted, Borla Touring AB, ProCal Tune
Full Shelby/Kicker Audio Upgrade
The 2016 will have a new, non-Microsoft sync system that's hopefully, better sorted than the one on the '15 and earlier models. That'd be reason enough to wait.
I took delivery of my 2016 over a week ago and the new Sync is exactly I was waiting for, and it was worth it. No more rebooting the car to make a phone call, and it hasn't randomly changed sources or given me any of the oddball behavior previous Sync did. It's quick and responsive, and the voice controls are much improved.