Replying in this thread, even though it's a necro its sort of on topic.
My ls got into a discussion yesterday about what to offhand: twilight or onyos. I've been thinking about this and I've decided on onyos for these reasons:
1) you need to fulltime onyos if you want to keep the haste buff on, it will keep falling off and you will keep losing either buff time or tp if you play the swapping game.
2) twilight is a 3% chance on a big proc. that's just not enough to be reliable.
3) nothing is more important than healer mp, even in abyssea. I don't want them to cast haste when I can do it myself.
4) slightly lower delay makes for faster dual wield.
5) 15% magic haste makes all my other haste worth that much more.
6) if you do manage to quad attack, you didn't triple attack (from atma) or double attack (gear, atma, saber), making those abilities and gear worthless on that hit
7) For evisceration only: this is a five-hit ws. You can only have eight attack oppotunities in a round. I'm not even certain you can get the quadruple attack to check on this ws if you miss a hit, although you could with the new merit ws. At a 3% rate.
Thydonon - PUP99, SAM99, WAR99, DNC99, BST99, SMN99, BLM99
Pandemonium rest in peace.