Hi DJFish. Well, the ACO online booking system does have it's vagaries but is getting better (I bet I rue that comment when it opens for business in a couple of weeks time
). As I have mentioned elsewhere there are still difficulties in getting what you really want, especially for the more popular sites. Even as a member there seems to be no logic in what is allocated. Ask for MB and be offered Bleu Nord or Beausejour one year, Get MB the next year, and so on. Just like the old days......
Unless you are ordering a reasonable quantity of camping passes, or want certain grandstands then I can't really recommend joining any more. I continue to be a member purely to be able to buy ACO grandstand seats and to be able to use the Welcome facilities at Dunlop and the Ford chicane etc. The pack of post race detailed information, souvenir poster etc. that members get is nice, but for me just ends up in the attic along with the rest of the ever growing memorabilia that my kids are one day going to have to sort through and wonder why I kept it all.
You do get discount on ACO merchandise as well and the use of ACO the washing/toilet facilities etc at the bottom of their grandstand even if you do not have a seat, so it really depends how you justify the cost of joining. This year for 'Passion 24' level membership the cost was 105 Euros.
In summary, and my experience, I wouldn't join purely to hope to get 'priority' on access to certain campsites, but take your chances when the online booking opens. Others may advise differently.
Pete B.