The Mk7 is a huge step forward / upward from the Mk6.
There was only one year of Mk7 TDI - 2015 - and only the Golf / Sportwagen, so that pretty much eliminates the Jetta.
DSG - meh. I'm not a fan, but with a tune, it's more palatable. I'd still always prefer a 6MT. My wife, OTOH, loves never having to shift, particularly in heavy traffic. So - depends the driver.
Trim level: Again, totally depends on the driver. Lots of folks here prefer the base level because there's less stuff to go wrong. I prefer the top trim level because the sport seats in the SEL/Highline are a HUGE upgrade over the S/SE trim level; and the sunroof. (Again, some people run in terror from sunroof, but even living on Vancouver Island where we get plenty of liquid sunshine, I'd have trouble owning a car without one).