I was away from the rift for four weeks due to circumstance, and got back into it last night. It wasn't nearly as blurry as I remembered, I was astonished at how sharp the picture was!
I suspect the rift wasn't sitting properly on by head before, and after adjusting the straps I get a much clearer picture.
Dammit, I could live in that thing if I didn't have to work, eat, shower,......!