We have been using the FZ300 for several months now for our Youtube channel and personal pictures and video. It replaced our Canon VIXIA HF R700 Full HD Camcorder. The ability to shot 4k or even 1080 @120 was impressive to us. To be able to take 4k pictures was a great sale point to us also. We were looking at a Canon 70d and lenses but this FZ300 just eliminated the Canon. Battery life is amazing. There is a learning curve but it want take you long to be able to shoot 1080 @120p with stabilization.
It's the First camera like this we have used. We always used camcorders for video and point and shoot for digital pictures and a Nikon for our 35 mm pictures. It is well worth the money and you will enjoy not having to fool with lenses. We do have a few filters and a glare cap for our FZ300.
Hope this helps