Not one to miss an opportunity but, if you're not a member of Brittany Ferries Club Voyage scheme and you want a 10% discount, send me an Email to dbooth899 at hotmail.com and I'll send you a code.
------------- How come when some people visit the fountain of knowledge, they only gargle!!!
I'm going to buck the trend and say A88, Alencon and Le Mans. Slightly longer but slightly quicker (according to Google)and easier. On the A84 you will need to negotiate around both Rennes and Nantes. On the A88 you don't go round any cities, even Le Mans is avoided really.