It really depends on what you want to do with the electric. I have both – a Fishman pickup on my acoustic and a Zeta electric.
The electric is great when I am playing in a full rock band – it does NOT feed back! The pick-up on the acoustic is great if I just need some extra volume.
It’s important to know, however, that with either one, you will probably need some sort of preamp to get the best tone from your violin. Some amplifiers are specifically made to help here (like the Fishman Loudbox) but with many, you will not have enough power to get the best tone with out the preamp.