People love them....people think they're fun (well, not everyone ofc), but most people have no clue about how it works.
Most know the basics...if you KO someone half of the bounty goes into your account, half will be added to the bounty on your own head.
Though, loads of people do not realise their equity in certain hands change drastically because of the bounties of the other players.
In a regular format, having a flushdraw and facing a raise might lead to an instafold if we don't get proper odds
In a PKO that same raise might make it a snapcall because of the bounty involved.
Ok...ofcourse there's also a lot of players who figured that out themselves.
Still, most of them don't realise their own bounty makes their raises profitable to call by their opponents, whereas in a regular format it would not be.
Just something to think about when playing these PKOs.
About the original question, yeah, you have to win to keep your own bounty, which means if you manage to get HU you're playing for the difference between 1st and 2nd, as well as the bounty of your opponent, as well as your own bounty.
Realise these bounties in a PKO can be significant after a while....