A colleague has used Beauvais and had quite a decent experience. Apparently there is a bus for each flight, as mentioned above, which arrives at Pte Maillot 1 h 40m after landing.
Bus from Pte M to BVA is 2h 45m before takeoff.
if you want to check, Paris terminal enquiries are on +1 58 05 08 45.
BVA enquiries number is +3 44 11 46 66.
Hope you have a nice flight.