Curation can be rewarding if you are manually doing it. Because you feel you are providing people with the money they deserve from good content but it isn't always easy to work out the best way to maximise revenue if you go for that and prices keep fluctuating.
Personal preference, really. What you like to do then go for it, but don't go hogging it all when you can give back to the Steemit community to help it become better.
I manually curate with approx 20% of my stake. The rest is delegated out for a set monthly payment.