Nicely informative.  It does raise some other questions, though.

1.   Has the power-down period changed?  I thought it was weekly for two years -or 104 installments.  But now it's 13 weeks?

2.  Is power-down all-or-nothing, or can it be applied to a percentage of SP?

3. Is delegated SP always kept separate - or is it merged at some point?

4. So the valuation for SP is the same as STEEM?  I ask because I entered the sum of my SP and delegated SP, then applied the current price of STEEM, and it wasn't quite the same as my estimated account value.