Good morning Ginodan,
Thank you for your inquiry.
They are both good sounders, but each have the own benefits. For example, you mention you have a TZT Touch MFD. The DFF3 networks to that machine, so you will view the sounder picture on the display or multiple MFD's if you have them in the network. Which means if you have multiple MFD's you will be able to not only look at the sounder from different locations on the vessel but also control the sounder at different locations on the vessel. Also the TZT has a much brighter screen than the FCV295 meaning it has more backlighting which will make it easier to see in direct sunlight.
Converesly the FCV295 has some features and filters that are better than the DFF3, like TVG. The TVG filter for the 295 I feel is superior than the DFF3 because it allows you to control the level and also the distance you want to set the TVG curve to.
However, both will do you right. The CA50/200-12m is a good transducer. Please keep in mind this transducer does not have a temperature thermistor built in. So if you want water temp you must add a water temp sensor to the the vessel and wire it in. The CA50/200-12m is also a very good transducer to help truth the bottom using the bottom tail and 2nd and 3rd echoes. It has a higher q value than some of the traditional higher powered Airmar transducers so it will draw you a very nice bottom tail that can be used to help show differences in bottom hardness.
