Pick an update for the human body
Less mucus, does not address excess mucus problems by creating more mucus
Fevers aren’t dangerous or unpleasant
Less fragile (both soft and hard tissues)
Stronger, faster and more agile
Intentional change (exercise, etc) is much easier to achieve and maintain*
Brain patterns easier to change
Stronger immune system; sickness of any sort is harder to get but still sucks
Base five senses greatly improved
Unpleasantness of physical pain highly reduced, benefits/awareness remain
Add three features from other animals (claws, tail, night vision, venom, etc)