Steempower is Steem.
If you are converting SBD from posts into steem to power up, that is good. If you are buying Steem on an exchange to bring in and power up, that is good. if you are trading SBD on an exchange to get higher amounts of steem, good.
SBD is meant to be pegged to one dollar US but has broken the constraints which means using it to buy steem now is a good idea but, SBD is very unlikely to be a hold coin. Steem is the valuable one imo.
THANK YOU! All of these questions are going through my head. I appreciate you answering them. Still confused about the advantage one creates over another.