This is an excellent question.
The movement is clearly better on the Tudor (especially the 70 hour power reserve and the precision).
The Aquaracer is thinner, it looks smaller while both have a 41mm diameter. It's more pleasant on this point.
I prefer the ceramic (and black) insert of the Aquaracer GMT.
I prefer the Tudor bracelet, thicker, stronger and with better finishing on the bracelet but also the buckle.
If I had to choose only one, it would be the Tudor Black Bay GMT (this is my 9th Black Bay GMT since the launch in June 2018 and it is my 3rd Aquaracer 500m GMT).
I also owned the Black Bay Pro for a few months. I didn't keep it because I find it too small, the 39mm is not for me and I prefer the 41mm.
This morning :