Thanks for your insightful and informative reply!
As a NEWB I didn't realize that my upvote power and my daily action-points were tied to my steem-power. If you want to level-up, steem-power certainly helps.
Also, there seems to be a lot of chatter about steem "inflation" and "dumping" and "burning".
Powering-up your steem addresses all of these "problems" at the same time!
I also wanted that steem logo next to all my posts! It seems to make them stand out a little more in the crowd!
Thanks for the info about SBD. It's a little weird to have two independently valued denominations of the same steem-money.