I notice the boil performance score is the speed to boil 1L of water and shown as a percent, but the actual times are omitted from the review. If I missed it, where please. If the fastest was 100% it could be discerned one at 75% could take 1/3 more time, so that is useful, but none are 100% so that is not your algorithm.
If ‘one’ takes 2 minutes and ‘another’ 2 minutes 20 seconds it might not be interesting. If the ‘another’ took 4 minutes it might be a deal breaker compared to ‘one’.
Has oversimplification happened where useful information has been filtered out?