I'm finding it very helpful because I'm so immersed in the story it's flowing much better and very naturally. It hasn't been without its traumatic moments though. When I used the F word I came over all peculiar and giggled embarrassedly to myself, and at one point, when the heroine was talking about something she struggled with, I had to take a break to emotionally regroup.
So this exercise for Lent has been my most productive and useful to date, much better than giving up or doing without. As I said initially, it's not for any religious reason that I choose to do something for Lent but just that the discipline seems to work for me.