Hmmm, I'm reconsidering.
Plenty of comments on the Overclockers forum suggesting the 4080 SUPER is only 1-3% performance gain over the 4080.
Asus TUF 4080 Super going here for £1,200 ish, so I'm now sorely tempted to bite the bullet and just go for one of the Gainward or Palit 4090s which are only £400 more.
Haha, listen to this madness!