I wish it were possible to achieve an entirely non-human body, but I don't think that's going to happen within any of our lifetimes.
In all seriousness, at times I do genuinely wish species transition were possible. Imagine gender dysphoria but for species, so species dysphoria. It may sound insane, but honestly so can the entire concept of dissociative identities.
I don't know if I'd want to change my brain, but the physical properties of the body definitely. I want the body to be a fluffy quadruped...
Thank you for the link though, that is very interesting. It is intuitive, but not something that normally comes to mind~