At the moment I would suggest taking 100% of your reward for a post as Steem (Select "Power Up 100%") as seen in the image below.
Even the 7 days you have to wait for your SBD's is a significant loss of value. If you use bit bots or receive some good upvotes in the first few hours, inflation on your SBD's portion of the payout will be more or less 11.2% over the 7 day waiting period.
I am, from now on forward, going to select 100% Power Up and will just power down the Steem I have available as Steem Power to have some Steem available every 7 days with which I can work. I'll never hold SBD again.
RE: Never Hold on to SBD! They Are Being Devalued At 583.8% Annually (48.65% Per Month).