Both cars are good enough and have their own forte. Both the cars offer good comfort but Porsche 718 offers comparatively a bit stiff ride quality as compared to Z4. Whereas, Porsche has better handling. BMW Z4 is roomy and comfortable enough for long drives. It is fast, has better sound and has better tech too. If we talk about Porsche 718, it defines a sports car more as compared to BMW Z4. If you want a fun to drive car as your primary car for daily commutes and long drives, BMW would be a good pock. On the other hand. If you have already a car for your daily usage and looking for a secondary car for occasional fun, you may go for Porsche 718. Do take a test drive before the final call. Check out authorised dealership details. You may compare both the cars also.