Sushi Dai is good but not worth standing in line for an hour. There are dozens of restaurants along Shin Ohashi Dori with local specialities and no tourists. For my money, I'd rather get a lunch reservation at Kyubey or Sushi Iwa than stand in line forever to get squeezed (literally) into Sushi Dai or Daiwa Sushi. There's a great coffee place a couple blocks away called Turret Coffee, ironically tucked behind a Starbucks.
And please, don't bring a suitcase. I honestly cannot believe the throngs of tourists I saw last time bringing in full-size roller suitcases. The market was not built as a tourist attraction—watch where you're going, accept that your shoes will get dirty and don't bring bags. Or touch the fish.
The market is worth visiting, especially if you're coming from the US, meaning the jet lag will have you wide awake at 3am your first morning. Embrace it and head on over.