I had a dilemma when i bought my M -the most stunning bronze coupe (which someone on here bought, not sure they still own it) this my favourite colour on the Z4. Did not want a coupe really and the dealer was hideous, but the colour combo was to die for, but then got in the roadster and found a lovely red black leather on an imola and was totaly . Go roadster.
4 roadsters now slk, tt, z4m and the M repalcement alfa spider. I cannot go back to a coupe, nothing beats having the roof down, especially on a sunny winter day, heater and heated seats on so you are warm and toastie, nothing better. Have to agree the coupe looks better but the experience in a roadster is for me better.
As you like both look around for a colour combo that whows you, then everytime you look at it on the drive or pass a shop window (sure we have a crafty glance to see how great our cars look) it will just add even more to the excitment of owning the car.