I can usually get up to around chain #19 or 20 solo before it falls apart. I dunno why. Does the time allowed between mobs get cumulatively shorter with each chain? I always thought it got shorter but then reached a limit. Maybe that's just with XP chains, which always seem to last much longer.

Anyway, to the original question, I'm definitely getting more CP than I did during standard CP, but it doesn't feel like it's more than the normal double CP. Also between now and the last time I did CP on MNK, I added another 135% in bonuses (from Rhapsodies completion and a new Gift).