Above 8% APR from curation is great in my opinion; it's actually my target. I also have no idea how some accounts get 16%, but I suspect it's through some kind of exploit. I could be wrong and maybe they're just very dedicated.

I also tend to lean towards the accounts I already follow because you could say they've earned my trust since I've read their blogs or watched their videos so many times. I do try to explore accounts I've never engaged with because everybody deserves a chance at discovery.