Not that I'm complaining BUT why do you get 4 transfers on a rest day? Surely you should still just get 2?
There are a few reason's i can think of,
1. Normally riders know they have the day off so will give it their all resulting in a few things, Moving up in rankings (cobo for example) meaning some of your riders could be left behind and you want to change out more than two guys
2. They give it their all and end up so knackered or injured that they drop out on the rest day
3. Some guys are just trying their best for the team knowing they will withdrawn at a certain stage because they feel they cant give anymore, thats normally a rest day
4. This one is specially aimed at La Vuelta this year, they want to do well at the world championships and feel they have done enough work to get in shape and its time to go, For instance, if Froome and Wiggo had lost 5 minutes today. i think Wiggo would have left and aimed at the worlds
So many more reason's, but i think rest days give you a chance to reconfigure your team about a little after only having two changes a day