If you like the look of the A5 but want more power and the growl of a big V8, buy the 2015. It has a lot going for it with IRS, it's pretty good looking (though sometimes it looks like a small Fusion) and I read they changed the manual transmission. Lots of cool features as well. I do think it's risky buying the first model year as they have more problems. I also own a 2012 Jeep GC and when I review the TSBs on the Jeep forum there are boat loads for the 2011 and very few for the 2012. Doesn't mean it will happen with your 15 but definitely a higher probability than with a 14.
Lastly - why are you looking to get rid of your A5? I have thought about trading the Jeep in for one from time to time. Love the Jeep but the A5 looks great and seems like it would be a blast to drive.
2014 GT Premium, Sterling Grey, 6 Speed, 3:55 Gears, Comfort Group, GT500 AB, 3dCarbon Spoiler, JLT CC, Boss 302 Alcantara steering wheel, FRPP TrackCal, FRPP Brembos, FRPP Wheels