I am in the final period of my NPPL at Conington and would say to you come up and see Gavin and Julie and get a feel for the set up.
I looked at Sibson and they to are friendly however the fact that Conington has a Tarmac Runway swayed me over Sibson and the problems with grass in the wet Winters (or Summers!).
A14 is problem but plan your lessons around the peak periods.
Whoever you choose - Happy Flying.
The Member