I don't see how the cost of additional prime lenses should factor at all into whether or not this camera has 8/10 bit for it's price. You keep referencing the X70, but that has a 1" chip compared to the full frame sensor in the a7sii, so that isn't a fair apples to apples comparison.
What does using a RED have to do with not understanding LOG workflow? If you convert your REDCodeRAW R3D to a REDlogFilm gamma curve, you'll certainly need to understand all of the points described above.
Preamps. Preamps. Preamps... this is one of the biggest factors in the overall noise floor and reproduction qualities of any field mixer or recorder. The high end setups will usually use a dedicated field mixer, which is then fed into a field recorder, because the preamps on the mixer have a lower noise floor. High end units like the Shure FP33 will retail for around $1500-2k, just for the mixer. Lower end units like the Tascams, Zooms, etc. will generally retail for under $300, but will also have fairly low quality preamps.
Also, like others have mentioned, there are other features like number of XLR inputs, timecode, record modes, outputs, etc. that will make certain recorders better than others.
One of the best field recorders as far as preamps and noise floor is the Fostex FR-2LE, which retails for around $500, but is one of the best recorders you can get this side of a Sound Devices or Shure unit.
Are people seeing the update available now through the main CC app?
Dell Ultrasharp line is quite good, also look into the ASUS PA249Q 24"