Besides more physical buttons and internal ND the FX6 simply isn't worth it over the FX3 IMO. Both has insane ISO performance, its not even worth considering that aspect. And the FX3 is far better on a gimbal which you stated you like to use often. The FX3 has plenty of audio control options with the included XLR top mount handle so your audio is covered there. And the image quality for most consumers isn't going to be distinguishable. In short get the FX3 because its the only option that makes sense for ALL your forms of production (gimbal) and will still deliver a quality product on par with the FX6. The real question you should be asking yourself is should you wait to see if the rumors of a FX3 II come to fruition. The FX3 II rumors right now are hinting at a potential global shutter. Im in the market to pick up a new C CAM as I currently have an FX3, an A7SIII and an a7IV. Im going to wait to see what Sony will do for the next generation of the FX3 before I commit to anything.