Steem Power equals STEEM in many ways, other than the small amount of interest SP receives, and the inability for hackers to quickly steal SP. Pros of SP are: security and small interest received; Cons of SP are that it is not a highly liquid asset since it takes 13 weeks to cash out. As for the SP bandwidth, I believe this is only personal bandwidth and it is not like EOS where you could sell it for a regular income.

SBD is okay if you can buy it under $1 USD and you monitor the community to see if they ever fix how it works. If SBD gets fixed it is junk then.

STEEM/SP should do well into 2018 as SMT's come online.