Thanks for your feedback
Main reason I want the door is noise and aesthetics. Should be an extra layer of alu between me and the fans and hopefully filter out some of the whine (Place to put soundproofing foam if I decide it needs it). Also it will make dusting down the outside a lot easier, as exposed intake mesh is annoying to clean regularly, gathers dust like a retirement home sofa (again speaking from the 900 experience).
I think in a case the size of the A70/A71, the door shouldn't make that much difference as the surface area available for air intake on the sides and bottom of the door would be OK in most circumstances. I rarely crank my fans up all the way, so if I needed to I could just open the door if I was stressing the system.
As you have the A70 which is the same case -door, you mentioned the cable management not being so good? It looks like there is quite a bit of space behind the tray for cables? Have you rotated the front HDD cage at all, I read a review that said it is a mammoth effort with the number of screws needing to be removed.