Here's an interesting youtubers take on the relative weights and prices of DSLR vs mirrorless systems.

My only concern with his lens lineup for the Nikon is the use of the lowly and massively incapable 70-300G lens, where the much more capable 70-300VR version should have made it into the lineup instead.

So if you replace his use of the non VR 70-300, with the VR version it only adds $300 to the price of the Nikon kit(so still cheaper) .. AND .. it adds 320 grams(2887g total), which then takes it to 3rd spot just behind the Sony A(at 2854g) .. and only 200g lighter than the lighter mirrorless system!
(but add in the point that you need 3x the number of batteries for the mirrorless system too to maintain shooting time, and that 200g becomes unimportant! )

I get his point; that with the current products available for each system you can setup an all round lighter set of stuff for your DSLR system than you can with a current mirrorless system. But it also needs to be appropriate gear as well.

ie. .. I'd highly recommend against using the Nikon 70-300 f/4-5.6 lens, and spend the small premium and get the 70-300VR lens instead.

What I'm more curious about now is how compact these kits are relative to each other.