I think something like 30-50x EXP would probably be sufficient for a v55 nowadays. Old maple was such a grindfest that 10x back then would be about as fast as 1x on current GMS.
Anyway, part of the problem finding a good throwback server is that they've been done to death. It's one thing for a throwback server to first appear a few years later, but v55's have been running since, well, OdinMS v55. They've been improved upon slightly and customized to death, but ultimately, anyone who has really wanted to go old skool maple over the past years has already done so and quit again out of boredom since it got stale.
*swishes his red foxie tail* Elevator Action is the best type of action.
Actually I think something like this would be a good idea. If Nexon some how managed to streamline a few things, cut some of the fluff, got the file size down and put up a separate download, I would consider playing that.
"You have your invincible spell!" Kerberos - Card Captor Sakura, El Nido Bow Master