I finally had the chance to dine at Urasawa last week and since much more talented photographers have documented the meal in exquisite detail, I won't even try to repeat them here.
In my opinion, the meal and experience was outstanding. The kaiseki meal was easily one of the best dining experiences I've had. I would put it just behind Pierre Gagnaire and Joel Robuchon and well ahead of everyone else including French Laundry.
The cooked and prepared items were delicate, refined, and at times genius. The edamame tofu with sake and mirin marinted ikura and the hairy crab with uni were phenomenal. The sayori was amazing, and the toro was as fatty as I've ever had. The chopped saba with kyoto miso was genius.
However, in my opinon, comparing sushi alone, Urasawa is an easy notch below Yasuda and Mori. Yes, the quality of the fish is pristine, however the rice is soft and lacks the perfected seasoning and texture that Yasuda and Mori have acheived. One does not get the pearly sensation of each well seasoned grain of rice that one can taste at Yasuda and Mori. I found the rice at Urasawa to be a bit soft and lacking in flavor and texture. The quality of the rice was more on the level of Zo. Mori has higher quality nori and Yasuda was a much larger selection of exotic fish. While the Santa Barbara uni was good, I found myself craving the Hokkaido uni that Mori serves. Yasuda's eel preparations easily win hands down.
On sushi alone, I would still have to give a 10 to Yasuda, a 9-9.5 to Mori, and a 9 to Urasawa since I personally give at least 50% weight to the rice.
Overall though, the experience itself was amazing.