The best bit is the nice new tarmac between Great Shefford and Wantage. Brilliant corners, theres only one you need to drop below national speed limit (ahem!!). Never seen any cops but watch out if the A34 is snarled up (you'll see it on your right if your heading North) as it turns into a rat run, full of artics and a big smelly traffic jam into Wantage with some 'interesting' filtering opportunities. My advice is to turn left at Letcombe Regis and do the B4001 / B4000 loop through Lambourn back to J14 - hyper speed. Just watch out for the horses, they tend to be worth a few bob ;-).
Great selection of bends that would suit different types of rider, mostly good visibility and pleasant countryside (also usually not too much heavy traffic) environment make this a nice run for a variety of bikes/riders