Read about Alinea on the New York boards in April, and rushed to the Chicago boards to find out more for our trip in June. Was able to get a reservation for a Thursday night at 6:30 (whoever said it's like calling for Oprah tix was exactly right!). Was initially bummed out about the time, but after our dinner, realized it's actually good to come early for what's a long meal (unless you want to be eating at 11 at night).
I had no experience with Grant Achatz restaurants (I went to Northwestern, but in the early 90s and anyway I was too poor then to eat at places like Trio) although I've eaten at WD-50 in New York several times.
Some tips: I thought the first room on the second floor (closest to the street) was the nicest. Although the decor is kept minimal to keep the focus on the food and the outside is obscured by curtains, that room felt airy and lighter and also you weren't near the bathroom. The room on the first floor seemed a little out of the way.
Service: The service was excellent, although I noticed a marked difference in knowledge and presentation. You get a variety of different servers presenting different courses. I thought some of the servers sounded like they were reciting passages that they had memorized. The best server was the sommelier (who also did food courses) who had a shaved head, funky glasses, and a tongue ring.
Wine tasting - important for light-weights: I did the wine tasting with the 12-course meal (tour one) and I was completely drunk by the eighth or ninth wine. They do a 2-2.5 oz pour and give you 10 wines - so you're drinking close to a bottle I think all said and done. It cost $80. The wine was great and I loved the sommelier, but I kinda embarrassed myself toward the end by babbling too much. Should have stuck to a glass or two. You can also request a printed list of all the wines you're served, which I greatly appreciated since some were so delicious I would definitely want to seek them out.
And last but not least - the food: Wow. Spectacular. The bison and rabbit in the 12-course were revelatory - totally different than other times I had eaten those items. I would recommend not changing or substituting anything on the menu - even for things you think you don't like - because every taste is so unique. My husband requested a change to the rabbit since he usually doesn't care for the gaminess of rabbit, and got pork tenderloin instead, but the rabbit wasn't the least bit gamy (and tasted much better than the pork I thought). I was kinda surprised there wasn't anything with duck though. I absolutely adored the hearts of palm course and the broccoli with grapefruit.
Alinea was a great evening and I'm so glad I had a chance to go there. We also ate at the West Town Tavern, which was fabulous. I have to say I'm very impressed!