it is very good but you don't need to wait that long to get that level of food. other restaurants in the area are pretty darn good too. there is another sushi dai outside the market that is good too (no connection evidently by the way...)
I swear that Sushidai is one of the best sushi restaurants in Tokyo. There are many sushi restaurants in Tsukiji fish market but remember, some of them are not so great from Tokyoite's point of view. If you have no plan to come back to Tokyo for a while, or want to try freshest sushi, definitely go to Sushidai and wait for a loooong line... Again, I swear you will never regret even if you spend more than one hour for just waiting. Actually, if you can have your seat in an hour or so, you are lucky. It often takes more than two hours if you begin waiting for the line after seeing tuna auctions in the market.
This tiny sushi restaurant (only 12 seats!) offers three course menu but you should try "Omakase", which is chef's recommendation, at around 3,600 yen because the chef literally select the freshest ones which were just come from the market. Omakasa set comes with 11 pieces and a roll.
If you dislike the taste of sushidai, I have no sushi restaurants to recommend you in Tokyo...