I can only compare it with an old Netgear N600 dual band router.
The Wi-Fi range and stability have been massively increased. Purely subjectively, I would now assume that I have about 50% more range than before.
The old N600 had already given up the ghost on one wall and one ceiling. Now I have full Wi-Fi reception in the same room with good performance (approx. 10-15m airline to the router).