Driven the 2.5T on track, hugely capable, surprisingly laggy but if you can look past the engine downfall its a remarkable weapon, but for me the engine is a major let down no matter how much horsepower it tunes too. But saying that the whole 718 is a let down even the 4.0l cars, they are very quiet. Handling perfection though!
981 GTS is the one to buy, just be weary of the Porsche bubble but residuals no matter on a 981 GTS or GT4 will be strong, if you can stretch to it buy a 981 GT4 for circa 65k, as a decent 981 GTS will be 50-55k so I'd always suggest the extra 10-15k worth it for big wing alone.
Still as a road car the 987/997 are a far more enjoyable experience on the road, huge fun, better gearing, hydraulic steering and very reliable and solid residuals. Cayman R would be my pick with a manual, you won't find a more enjoyable Porsche for the road and they are very capable on track. Otherwise 997.2 GTS is potentially the best road car Porsche ever made! Solid prices because solid cars!