I don't know what the actual rate is, but even with a power down running I make more SP per week than pays out on the PD. I decided to do the power down because I like the liquidity coming in without having to go crazy writing and promoting a post. I had been exchanging my the PD Steem for BTC each week when I got it, but I've decided to stop doing that (for now at least). What I'm trying to figure out now is whether it's more beneficial to the whole Steemit community (myself included, of course) to keep my holdings in Steem or SBD. I see value to doing it both ways. Perhaps I should just split it 50/50 across Steem and SBD.

But to get back to your point, I don't find any obvious value to staying powered up instead of powering down.