Do you love the light weight, form factor, variable ND, and 120fps (HD) of the FS5 but prefer the 4K quality coming out of the FS7? You're going to love this firmware upgrade for the FS5.
This may be just the thing that puts you over the edge and makes you pony up for Sony's FS5.
By opening up the firmware to allow 12-bit, 4:2:2, RAW DCI 4K recording up to 60fps and 10-bit 4:2:2 HD up to 240 fps (I got these deets directly from a Sony person while visiting their NAB pavilion), Sony opens up significant daylight between the FS5 and the a7x II twins while dramatically narrowing the gap between the FS5 and FS7 (though the FS7 still has its advantages, like recording 10-bit 4:2:2 4K internally -- the FS5's SDXC cards can't do this, 4K being limited due to inherent speed and size limitations to 8-bit 4:2:0 -- the FS5 will rely instead on an SGI-connected external recorder).
While Sony's pricing is very aggressive compared to Canon's, what's often overlooked is just how smart Sony's pricing is: they are creating real differences -- read that as choices -- across an incredible range of products. The initial price/value of the FS5 was a little off Sony's game, but with this $600 firmware upgrade, it is a much more compelling proposition.
Take your pick: $7,999 for the all-in-one, incredibly robust, shoulder mounted FS7, or $5,599 for the dramatically more compact FS5 + $600 for the upgrade and $1,695 for something like the just-announced Atomos Shogun Flame (which together total $7,894, spitting distance to the FS7).