I see absolutely no point in requesting whole-head preservation when preserving only the brain (which is essentially the same thing) costs significantly less than having your entire head preserved at Oregon Brain Preservation.
The only argument I’ve found in favor of whole-head preservation is that handling a slippery and fragile structure like the brain might cause problems—meaning it could be damaged in the process.
The enthusiasm for aldehyde-based chemical fixation preservation seems extremely misplaced to me. Biological viability is lost, and the original proteins can no longer return to a normal state. Traditional cryopreservation is much safer if you're looking for real prospects of revival—at least, that's how I see it.