I wrote about my experiences with the vive pro earlier in this thread, saying the sweet spot is not that bad. Could be better... though admitting that I couldnt compare it to the Oculus since I haven´t tried that one.
But, this... this sounds just plain wrong. You must have a faulty headset. The sweet spot is by no means "tiny" no matter what one compare it to. And it´s not "come from clarity to blurry all the time during game play". Is the Oculus sweet spot much bigger? I don´t know. Perhaps so. But the sweet spot on the Vive Pro is not tiny. I wish it was bigger, but it´s no big deal when I am gaming or flying a simulator. And it´s not ruining the immersion. The overall sharpness just improves the immersion.
Anyway, I the Vive Pro is way too expensive. And the sound quality is bad. But the comfort is really, really good. And the clarity, resolution, black levels, contrast and colors are really good!