I’ve been using migration asst to transfer info from my old Mac to my new Mac Pro. It has been about 28 hours . Is this normal?

Could be, depends what Interface you're using & how many GB of data, last time I did it it was over 24 hrs as I recall.

Wifi is way slower than Ethernet.

Do not use wi fi. It is too much data for wi fi and it will often get corrupted in the transfer. You need to connect the two computers with a USB cable to ensure a satisfactory transfer. If it has completed and all files have been correctly transferred by now, then good. If not. I would cancel and redo with a cable. Normally, a transfer should not take much more than an hour or so. Good luck and enjoy your new Mac.

Any luck yet?