The B Pillar Rattle is real
My new car that I just picked up mid January has been been rattling on both B pillars. Service acknowledged the problem immediately and said Land Rover is aware of the problem and there is a fix. The fix involves welding. The fix can only be done at a body shop. The body shop here estimates 7-10 to get it fixed.
So this is a real problem. Check if your Discovery for this problem and if you have this problem, you can bring it in to Land Rover to get it fixed.
I got an Evoque as a loaner and in my opinion, it doesn't come close to the comfort of the Discovery. The Discovery has much more room inside. The Evoque feels a little quicker on the start and I"m pretty sure that is because its a lighter car.