This is the most up to date white paper and still has the peg to the dollar via interest rate adjustments in the code. https://steem.io/SteemWhitePaper.pdf
"The primary concern of Steem feed producers is to maintain a stable one-to-one conversion between SBD
and the U.S. Dollar (USD). Any time SBD is consistently trading above $1.00 USD interest payments
must be stopped. "
Bottom of page 11 under the Steem Price Feeds section.
The Blue paper is a dumbed down version of this designed for everyone. If you are seriously investing and telling others to invest as well, you should really be reading from the source in my opinion.
RE: STEEM vs SBD....DO NOT UnderEstimate SBD!!!