
Weight is in the manual's corner. The manual GTS weighs 3295 pounds compared to 3335 pounds for the PDK GTS. Not a huge difference but a difference nevertheless.
As for acceleration, well, the PDK wins naturally. Although the manual numbers are very good:
Manual
0-60 3.4
1/4 mile 11.6 @ 123
PDK
0-60 3.0
1/4 mile 11.3 @ 125
These are magazine figures so slightly inflated but the GTS is putting up 991.1 Turbo level acceleration.
If you put an emphasis on acceleration the PDK is the way to go and speaking from experience a spectacular transmission. Honestly, you can't go wrong either way. If three tenths of a second isn't a big deal to you is there any better turbocharged Porsche available with a manual transmission than the 991.2 GTS? The answer is no.

Specifications
VEHICLE TYPE: rear-engine, rear-wheel-drive, 2+2-passenger, 2-door coupePRICE AS TESTED: $128,980 (base price: $120,050)
ENGINE TYPE: twin-turbocharged and intercooled DOHC 24-valve flat-6, aluminum block and heads, direct fuel injection
DISPLACEMENT: 182 cu in, 2981 cc
POWER: 450 hp @ 6500 rpm
TORQUE: 405 lb-ft @ 2150 rpm
TRANSMISSION: 7-speed manual
DIMENSIONS:
WHEELBASE: 96.5 in
LENGTH: 178.3 in
WIDTH: 72.9 in HEIGHT: 50.6 in
PASSENGER VOLUME: 70 cu ft
CARGO VOLUME: 5 cu ft
CURB WEIGHT: 3295 lb
C/D TEST RESULTS:
Zero to 60 mph: 3.4 sec
Zero to 100 mph: 7.8 sec
Zero to 130 mph: 13.0 sec
Zero to 150 mph: 18.6 sec
Zero to 170 mph: 26.8 sec
Rolling start, 5-60 mph: 4.6 sec
Top gear, 30-50 mph: 13.0 sec
Top gear, 50-70 mph: 9.0 sec
Standing ¼-mile: 11.6 sec @ 123 mph
Top speed (drag limited, mfr's claim): 193 mph
Braking, 70-0 mph: 141 ft
Roadholding, 300-ft-dia skidpad: 1.06 g
C/D FUEL ECONOMY:
Observed: 22 mpg
EPA FUEL ECONOMY:
Combined/city/highway: 21/18/26 mpg