My sons just bought his second one about a month ago now they really are a great car.
It appears that having the dynamic suspensions isn't that important unless you're contemplating track days. The BHP changes about 15 BHP between 2015 and I think mid 17. My son opted for the 67 plate as this was when the power peaked and they now have steadily reduced back down to 295 (don't quote me)
Make sure you find one thats had the haldex oil changes done, apparently very important on this model. Imo the later virtual cockpit dashes are a nice touch having the sat- navy screen directly in front.
The B&O sound system is amazing also. There's a few bodywork tweaks on the later models and I think in general they look better with the rear defuser and upgraded headlights.