Pre-purchase question here - is there any detail control on the AX100?

I don't think so - that's part of the reason for the X70. But, here's the manual:

Sony eSupport - FDR-AX100 - Support (http://esupport.sony.com/US/p/model-home.pl?mdl=FDRAX100&LOC=3#)

Yes, it's called 4K mode! Seriously, there isn't much in the way of tweaking the look. No custom presets. There is a "Picture Effect" menu, which has seven effects to choose from and includes one called, Pop Color, which "creates lively images by emphasizing the color". Then there's the other mode you can invoke, called Cinematone, which it says, "shoots with color/brightness as in films."

Mark

No. Aside from what is called "Cinematone Mode" which darkens the already dark shadows and brightens the already clipping prone highlights, I'm afraid there's none you maybe looking for. My US$450 Sony HX400V P&S stills cam has more useful picture-profile controls than the AX100.

The UHD image, however, looks highly detailed and gorgeous if you are very careful about exposure and lighting.