I definitely can't continue going longer than 3 days due to my sleep schedule and how it changes on weekends, so Saturday-Sunday-Monday is best for me. Since I've seen it recommended many places that you should have at least many days "off" as "on", I guess I'll switch to the 3/4 schedule come this weekend and see how things work.
Considering that the great feeling I tend to get during my "off" days tends to wear off during the second week, this might actually be best. But the only way to find out is to try it.