Just finished w5r1 for the second time and was pleasantly surprised. I ran it first at the beginning of last week, but struggled on r2 and then got a horrible cold... so wrote the entire week off! Restarted running w5 today and the first one felt so easy!! I was shocked as I thought that after not running for a fair few days and being ill that I may struggle, but I didn't at all. It's quite the motivator after a poor week last week! I would definitely recommend rerunning weeks that didn't go well for you.
Hopefully I'll be saying the same after run 2..!