For me, it depends very much on the vertical position of the headset. If i have it too loose and it shifts downwards, the image gets pretty blurry... it took me a half an hour to find the best fit and i returned to the IPD setup several times as well. My IPD is 64.5 mm.It varies.
On reddit I'm reading comments of people with 70mm IPD, and it ranges from "it's awesome and sharp" or it's a "a blurry mess, I'm returning it."
I would definitely try before buying, or at least buy somewhere with a non hassle returns policy.