Natural sound from a pickup?

I have been using a Shadow pu for a few years now and have been pretty happy with it. Since getting an EAiamp combo I have really noticed the big difference between acoustic sound and amp sound from the pu. I can play / get away with things acoustic that sound really bad using the pu/amp.

I have read a lot about the Realistic pu but I am not convinced enough to try one yet.

I know it depends on the bass & amp but i have a good amp and a good sounding bass. All I want to do is amplify that sound.

Do I really have to get a mic or is there a pu out there that can give a significantly more natural/acoustic tone?