The power is more than adequate with excellent low end torque. The engine is the most refined in any sportscar. Transmission is excellent with well defined gates. Clutch take up and feel is excellent. Steering tightens up beautifuly at speed. Corner placement is intuitive with no corrections necessary in steering feed. Run flat tires provide safety, consistent feedback due to very low flex, rim protection in potholes and excellent convertible trunk space. Interior is excellent in design amd materials. Excellent rear visibility with top up. Solid roll bars. Exceptional sound system even with top down at high speed. Minimal wind buffeting and noise at high speed. Excellent 2 stage skid control
Ease and speed of lowering or raising top, even from outside the car, with no need for a cover makes it a very usable convertible sports car. With top up you barely know it's a convertible. Everyone, including left lane hogs, pull over to watch it go by as they smile. Interior room.
Body style very sensitive to color choice. Power of vette, interior of maseratti, transmission of s2000. But hey, nothings perfect. Everything is compromises and the Z4 is the best set of compromises, including reliability, of any sportscar made today.