Lacroix or 4 Seasons for a vegetarian?
I'd actually say Lacroix...my sister is a vegetarian and it's one of her favorite restaurants in the city, so we will go as a family a lot. I think the ease of choosing your courses and the order, not to mention how accomodating they are in amending non-veg dishes, makes it a good option. You're not stuck with two salads or two apps there...definitely enough food. Enjoy either though!
Four seasons is better.
I made a reservation at Lacroix and told them at the time of making the reservation and again a few days before the date that I was vegetarian. When I showed up, there was just the normal menu which had few vegetarian choices, although they were happy to modify dishes for me. They did forget to describe all the ingredients, so I ended up with one dish with calimari on it (that my husband ate).
In comparison, my friend made a reservation at Four Seasons and told them at the time of making a reservation that she was vegetarian. The chef called her back asking for more details of what she can and cannot eat. I think he even called back to confirm something a few days later. When she arrived, her meal was as sumptuous, complex, and gourmet as her husbands. They had made several special dishes for her that met her needs and were excellent. Thank you.