I'd stay to the north of Oxford and pick up the A44 there, the A44 is a bit quieter than the A40 and a bit twistier. Fish Hill is a great set of sweepers if you get a clear run at them and worth it just for that. There's a roundabout at the bottom in case you want to go back up for another go...
That looks good, thanks, where would you recommend jumping on the A44?
Is this better then staying on A40 until A49 at Ross on Wye?