Blenheim palace or Macbike sportive

gog555

Looking to do what will probaly be my last sportive of the year can`t decide which one.
Got it down to 2 choices they are

http://www.bikeblenheimpalace.com/sportive1.html
or
http://www.macbike.org.uk/

What are peoples opinions of these rides??
I live in cambridge area so one is a lot closer but could be tougher the other one a bit more of a drive but eaiser.
Or does anyone know of any other decent rides i may have not found out about