Re: 2012 SRT8 or 2014 Overland?
The styling differences between the MY 11-13 and 14 are completely subjective, so that should simply play into what the OP prefers. As previously stated...if you want luxury with off road ability get the overland (and relatively good performance for a 5k+ lb truck with V8). If you simply want performance similar to your S4 go for the SRT.
BTW I prefer styling of MY 11-13, although the MY14 has grown on me. Love the flipper glass and dash layout. Seems much less clutter given all the options and I wanted the saddle interior.