[Brightcolours]

Regardless of the format f0.95 is f0.95, all you are seeing is shallow DOF, but consider other aspects, like available light for the AF system, try using flash lighting and you will find it in another league.

Yesterday was doing a sunset photoshoot using flashes to light faces with sunset behind, DOF was merely  the same however 17-55f2.8 was by far more useful than 24-105f4 on full frame ( my 50f1.4 was in another world really)

Many problems with your thoughts...

• f0.95 only means that the aperture is bigger than the focal length. That is what it means... What the size of aperture is only gets clear when you know the focal length.
  
• The AF system of your DSLR does NOT get more light with an f0.95 lens than with an f2 lens, for instance. It is a misconception that it does. The AF system has its own "aperture" which is the limiting factor. That is why Canon talks about AF points for f5.6 sensitivity and f2.8 sensitivity. It is also why AF points can get (partly) blind with smaller aperture lenses.
  
• F2.8 on APS-C is never "more useful" than f4 on FF. It can be that the more modern APS-C camera has some advantages over the decade old FF camera, of course.