Sorry to get to the thread late! The Irish place sounds fine if it's a done deal, I'm there.
BUT, let me share a bit of wisdom I picked up at a reunion in LV last year. Buffets can handle large groups with ease. Restaurants freak out when they get a group of 30, they watch you like a hawk, and are afraid you are going to tie up valuable table space all night yakking. They kind of pressure you to finish up and move out.
LV buffets don't even BLINK for 30 guests in a party. You pay in advance, so the single check nightmare/getting stiffed is completely avoided. You can stay for as long as the buffet is open, they don't care. And, you can push tables together anyway you like.
I attended a reunion for about 75 folks at the Harrah's buffet, it was ideal. The staff didn't mind, they loved us. We pushed together our tables into our own little clans the way we wanted to, we weren't jammed into a little room. There was no time pressure, and we could "graze" on the buffet lines for hours and hours....and we did! Talk, eat, schmooze, ogle, talk, eat talk joke laugh etc.
And no bill to divvy up at the end.
Matt