I don't recall any other tournaments that have the round robin format. I'm supposing that it's one loss and you're out for every other tournament in existence.
The tennischannel open in Vegas this year tried the round robin format and it sucked hard core. Players hated it, fans hated it and I think that tournament pretty much decided for the ATP that the format is just a no win right now for mens tennis.
Weren't a bunch of tournaments experimenting with the RR format last year? It was a grand ATP experiment designed for the fans so that they could see their favorite players more than once (if they lost). They wisely dumped it.
Maybe if they want to experiment, they can try a loser's bracket. That might be something to try. But, a venue would have to have the courts available.
Yes, the ATP experimented with the RR format earlier this season, but after the mess that happened in Las Vegas, complete with interference from Mr. Disney himself (and he didn't even know the rules correctly), the whole idea was dumped.
There is an exhibition before the Australian Open. 'Kooyong' Classic i think it's called, and most of the top eight go there to play. I remember Federer getting defeated there a couple of times by haas and roddick. But these wins/losses don't count becuase it's just an exhibition.