I'll say a mix of both.

I'm top curator at curie, at the break for the moment, and currently writing science curation for Helpie - with steem look up filters things are much easier to find.
In some other projects (teamserbia) I am in trail and manually curating from a main account and steemSTEM always hides some gems for a nice read - with crowdmind we only do manual curation.

So yeah, I'm leaning more towards manual curation, with just a sprinkle of automatization. :)

Cheers!

P.S. I really like all the things you bring up and discuss on network. :)