TKTS Questions...

My high school Model UN Club is going to be in New York City next week for a conference and everyone in attendance is interested in seeing a show... Unfortunately, I have only been to the city once before (my theater experience is limited to tours and OBCRs) and I'm not familair with the workings of TKTS... When does TKTS open every day and from your own experiences when is it the LEAST busy throughout the day? Furthermore, what are the odds of getting tickets to Sweeney Todd day of there? (One can only hope...)

Oh! One last question! We're staying at the Grand Hyatt Hotel which also advertises ticket sales-is that similar to TKTS or are they more expensive?

Thank you very much for all your help and I can't way until next Wednesday!

FYI, TKTS has also moved temporarily to the Marriot Marquis hotel (just across the street from where it used to be). There's more on this on their website.