"Will the premium service allow you to not only see stats on other users' performance, but also to automatically vote the same way as those users?" Yes, you will be able to follow any user.
"looking at accounts with similar amounts of Steem Power" This will be handled by using percentages. This way, even if an account has more, you will see the possible benefits.
This premium service will be available in a week or two.
Okay, makes sense, using percentages is a nice way to handle it. Looking forward to seeing more details of the premium service and trying it out if it looks like a good deal!