So ya, it was a great experience. Wife and I even decided we'd probably do it again in a year or two maybe in spring or summer for a totally different menu vibe.
What we did was order each supplemental, but only one so we could also try the non supplemental, so on the supplemental course we'd have two different plates come out and we'd eat half and swap plates. Worked out best for trying the maximum amount of stuff, although for the "legendary" oyster and pearls 1st course which is served year round, i'd highly recomend skipping the $60 supplemental (for the upgraded cavier) because the supplemental is an almost completely different bowl and you don't get the oysters but a trout cake. It was really good, and you could definately notice a difference in the 'pearls', but the OG oyster dish was so amazing we instantly regretted having to share it.
I'd say all other supplementals were worth the extra money. We got lucky and hit the window of white truffle season so the supplemental white truffle risotto was something i'd never thought would live up to the hype but dang it was memorable, and I have a feeling they don't make any money on it looking at white truffle prices online. It cost an extra $175 but I swear to god they shave at least half an ounce of truffle on your risotto in front of you (seems like more than half ounce really but I doubt it was).
The a5 wagyu was an extra 100 bucks but it was really cool to try, especially considering the non-supplemental counterpart was lamb, and although lamb is one of my favorite meats it was fairly underwhelming as far as the whole meal went.
Wine, we said fuck it and didn't really care about the price so we told the sommelier to pick us out three glasses to get us through the three sections of the meal (start / fish / meat). It was all great but added a total of $300 to the bill.
Major highlights in order were:
White truffle risotto
Oyster and Pearls
A5 Wagyu dish
Those will probably be the three dishes that I can conjure up the tastes and experience eating years from now. Everything else was great, but those stood out.
Total cost was something like 1200 bucks, which isn't a huge deal on paper for us but still seems like insanity for a 3 hour meal but it is a helluva experience. In the future we'd probably opt out of the wine and not get the oyster and pearl supplemental, which would have brought the bill down around 800, although if you know it's going to be the only time you ever go you might as well say fuck it and get the wine.
Some other random notes:
Wear the lightest sports coat, shirt and pants you can find. You're expected to keep your coat on during the meal and it can get warm.
If you really want to nail a special date for reservations and money is less of a concern, just get a reservation for 4 (they are always available a couple months out). We saw multiple couples that did this and they'll give you more dishes (looked like some special ones) and/or let you pick and choose extra plates from the vegetarian (garden) menu as you go.