IBIS helps with very static objects. Even for family pictures which are not 18th century style pictures, but people been alive and moving IBIS doesn't bring much. Maybe at long tele... But they say lens IS might works better on tele.
Noise reduction is only better on high ISO. But flash on low ISO still leaves high ISO in the dust. High ISO is still inferior to low ISO. Mirrorless or less mirrorless. Some are realizing how better low ISO is on old DLSR bodies. Clean high ISO is dual sides sword, apparently.
Lighter body? It is often only gimmicks. To match capability of DSLR on single battery, Canon mirrorless needs battery grip. Canon RP is failure comparing to Sony A7C on battery live, but Sony A7C has next to unusable EVF. It is so tiny.
Eye focusing? Do you know Canon has it in film SLR? Prosumer and Pro. I had Pro body with large AF covering and prosumer now with much less. Both are noting special and surprisingly doesn't improve photography much.
I think you mean "eye controlled focusing" and not "eye tracking focusing"?
In low light, I freeze the motion, balance with incident light and keep relatively low ISO. Win-win to me. Just a single, TTL, bounced flash works for me.
.....I have no need to reinvest in mirrorless when the top of the line DSLR's are so good. I am interested in this rumored R7 if it comes for fruition....The R3 is just too expensive for me to get into when I have so many other interests for my retirement years. If necessary, I will get a 1Dx3 before they stop making them...they are excellent and they do anything a mirrorless can do except auto eye focus
