Ive got both the matrix infinity and the passive fishman setups.
The matrix infinity runs a 9v battery that mounts in the uke and is a preamp active setup with optional volume/tone controls that mount in the sound hole. The sound in the active is more crisp and clean and louder then the passive. Both run senors under the saddle.
The fishman passive doesn't use a battery,the sound of it is very warm and pretty decent in my opinion for just hearing yourself. You also have the option to use a external preamp on the side to convert the effect of active pickup. Volume and tone controls can be added to this pickup but it needs to be soldered in pickup, sometimes you would need to wire in a resistor as well.