I have heard that West to East should give you a tail wind. Also the hills maybe steeper West to East with longer down hills Instead of a long slog up & short down hill East to West.
Im looking to do this over 3 days, camping West to East. I have found this web site helpful
You do realise that once you commit to that, you WILL have an easterly wind blowing on whatever dates you decide?
I did the Way of the Roses a few years ago, east to west. Fixed the dates but then waited until a few days beforehand to check the wind forecast!
The obvious downsides are you pay full whack for any trains you might have to use to get to the start or home; and if it's peak holiday season then accommodation might be a problem. I went midweek, during school term so no problem.