How is life balance in M3/M4?

Currently an M1. I'm doing really well in my classes but at the expense of having any sort of life. I would honestly say I'm doing 70 hours a week during a normal week and pushing 90 hour weeks during block weeks. It sucks, but I realize it's not forever and there is some semblance of light at the end of the tunnel. I want to have as many options open as possible come residency, so I'm committed to doing the best I can so I set myself up to do well on Step 1.

For those that are a couple of years (or more) ahead of me, how does M3/M4 compare? Do you find you actually have less time than you did in M1/M2? Do you find your schedule about the same as my current schedule? I know there are shelf exams, and long surgery hours, and Step 2, but I'm hoping I'll be able to pull back a little after Step 1. Thoughts?