For some of the path, there's just incline. For some, there are stairs. Some of that has a railing — a luxury that Herod's visitors wouldn't have enjoyed 2,000 years ago — and much does not.
Even before the sun came out, it was brutally hot and humid. This is not a climb for the faint of heart, though it is certainly doable with persistence and plenty of water. Estimates put the climb at anywhere from 45 - 90 minutes — it took us about an hour at a steady clip, racing to beat the sunrise.
Since the ticket booth to Masada opens an hour before sunrise, the only way to reach the top in time is to move relatively quickly. (There are cable cars that go to the top, but they don't operate until 8 a.m.)