As a daily voter, is there any disadvantage to converting all my Steem and Steem Dollars to Steem Power?

I see myself as a voting lurker, like I am on Reddit, so my best strategy would be to concentrate on Steem Power, correct?

Related question: if I want to convert some BTC, does it matter whether I buy Steem first, then convert to Steem Power, or is it a better bargain (less transaction fees?) to deposit directly to Steem Power?

Thanks for any help! =^^=