I'd buy the 997.2 PDK, really really superb to drive, modern enough.
As with all of the generations of Porsche, there is much being fettled underneath that most don't take into account, for example the PSM is many generations newer (14 I think) in my 997.2 C4S compared to our 996 C2.
That said I bought our 996 on a whim for the wife mainly (tlo avloid her driving mine) having had my 997 almost a year at that point and its remarkably good, far better than it should be for its years and mileage but mine is just awesome, a worthy upgrade.