Full Frame DSLR or Mirrorless

Hello, I am currently using a beginner DSLR - NikonD3300. I am looking to upgrade to a Full Frame DSLR or a mirrorless camera. If I go with full frame I think D750 meets my needs the best even though it was released 5 years ago. I mainly photograph pets (sometimes in motion running or jumping) and portraits. In my research everyone says that mirrorless is the future. So I am thinking maybe I should just get the mirrorless (price is not an issue for me though of course I would NOT consider something $6,000 as some full frame DSLRs are) My main points for what I am looking for are as follows:Great Dynamic RangeAbility to blur background IN camera (currently my crop sensor camera is not too good at that and I blur the background in PS)Ability to AUTO focus in low light conditions.Being able to capture action/motion (as I said I photograph a lot of running pets)Image sharpnessIntensity/appearance of colorsHigh speed sync (not a deal breaker but would be nice)What are your thoughts and experience on the subject. What would be the advantages of the mirrorless? I appreciate your advice, thanks

The D7xx are very capable bodies. They can provide all the
performance you are after. The mirrorless are good too but
the two tools are not equal when it comes to speed — read
sports and wildlife.

The difference comes from the view finder they use: OVF vs
EVF. In this, among other thing, the D bodies outperform the
Z ones (mirrorless).

ADDENDUM

The blur and the faster AF are mainly lens dependant.
I know the AF is in the body but it's the lens that makes
it's speed possible.

In my wildlife seminars, I explain that my 600mm ƒ4 is
used most of the time at ƒ8! "Why did you buy an ƒ4 for
so much money if you don't use it?" my students very
often ask.

The ƒ8 is for the sharpness of my subjects and the ƒ4 is
for the speed of AF system.

Nikon Shooter wrote: The D7xx are very capable bodies. They can provide all the
performance you are after. The mirrorless are good too but
the two tools are not equal when it comes to speed — read
sports and wildlife.

The difference comes from the view finder they use: OVF vs
EVF. In this, among other thing, the D bodies outperform the
Z ones (mirrorless).

Thank you for sharing your thoughts, much appreciated.

One advantage — that I still don't care much about— is weight.
I like the heavier and bulkier DSLRs that feel stable and comfort-
able in my bear paws.

Though the Z lenses not being much lighter, the Z bodies are.

While mirrorless cameras are smaller and lighter than dSLRs, that doesn't extend to their lenses, which are just as big and heavy as their dSLR counterparts. So the size and weight advantage quickly diminishes as your collection of lenses and accessories grows. Also, the shorter Flange Focal Distance of mirrorless cameras requires their lenses to bend light more in order to project an image over the entire image sensor, so those lenses are more prone to vignetting, chromatic aberration, distortion, and field curvature (soft corners). That is not to say that those flaws can't be overcome, but in order to overcome them, lenses must use more advanced and more expensive designs. Thus, most mirrorless camera manufacturers opt instead to process images in the camera to "compensate" for some of those image flaws. Unfortunately, that processing often simply replaces one image flaw with another, and worse, there is no compensation for the field curvature, and the compensation for distortion actually makes the corners softer. Further, mirrorless cameras are comparatively new, as are their lenses, whereas SLRs and their autofocus lenses have been around for decades, so a new dSLR can use many of the excellent lenses available on the used market at a greatly reduced price. And while dSLR lenses can be adapted to work with mirrorless cameras, use of adapters often introduces other problems in terms of both functionality and image quality.