I prefer the two-player arena format. I prefer bigger-room games for every other format.
In two-player arena format the waiting time for a game to start is significantly less. Players not playing or disconnecting happens too, but i feel it's less frequently. Games are also a little faster (of course it depends on the players play style and speed).
I get the point, that you don't feel ok with becoming last when you have a relatively high score. It happened to many players in many games. But in the end you want to win every game (I think) and thus have to beat the opponents score. So when you are not beating their score, you lose.
The same argument could be made in favor of the two-player format: Not scoring first and becoming last feels fair to me.
