It's got to be worth it to see all those Spitfires. I was at the BoB show in 2000 when they got twenty one Spits and a Hurricane up for the final flypast, amazing sight. I am a tad done about the Seafire and I've not seen a Brisfit flying for about five years.
Besides that, we are all looking forward to your photos

I'll be relying on you for the photos.

Those mass formations are very impressive to watch but I find it difficult to do them justice in a photo. I'm sure you will agree that the lighting at Duxford is all wrong so when the show starts you're shooting directly into the sun. This gets worse as the show progresses. That's if there is any sun to speak of as the forecast for Saturday is not promising. It's a long way to go to get soaked & those big air displays lost their appeal for me long ago. The relaxed atmosphere of the fly-in at Popham on Sunday suits me much better.

You can see a Brisfit at most of the Old Warden displays with a much better chance of a decent shot. Sorry but I prefer that to Duxford any day.
PS. I'm not trying to put anyone off so take no notice of me. It's just the way I feel about it.