Perhaps what's dissimilar is it's, rather than being more geographically directly, it's directed at the Jewish believer, and one of the striking dissimilarities might be the degree to which the writer of Hebrews warns believers, or warns the church as a whole about persevering in faith and not presuming upon their status as members of the household of God. So, the warnings of Hebrews are pretty stark compared to many other New Testament books.
But again, we can return to a similarity which is, say, in comparison to 1 Peter, affirming the pilgrim status of the people of God, that we are not home yet, that the world is not yet a consummated kingdom of God, that though he's been exalted, we do not yet see all things subjected to Christ the way we will one day see them as Hebrews 2 says.
Rev. Michael J. Glodo is Associate Professor of Biblical Studies at Reformed Theological Seminary in Orlando, FL.