I know someone said that it takes a long time and with exp caps from 15rc, which has recently become 20rc, and I'm aware this post is old, however the person said with getting exp caps from 15rc you get one level per month, which is not true. xD I got my earth to 180 about a month and a half ago, and she is now 184 just from exp caps from 20rc and the occasional cap from NT. I definitely think it's worth it to take them to 199. You won't have to worry about breaking their eq when doing quests at 180+, and even if you rb them at 199, they're level 100 so there's still some risk in breaking eq from some things but not as much if you rbed at lvl 180 and were lvl 81+ (rb)