When I lived in Japan I was close to a Gyu-Kaku and I went there a couple of times every month for AYCE. The service, the quality of the meat and the overall experience were always top-notch. The prices were good too.
So when I found out they were opening a Gyu-Kaku here in Vegas I was pretty stoked. The Korean BBQ places are a good substitute but not the same. I've been a few times since the opening and have always found the food to be good and the service is on point too. I usually make reservations to be safe but I've never had to wait more than a couple of minutes when I just walk in for dinner.
For whiskey fans they have a good selection of Japanese whiskys at the bar and the prices are good too. Bartender told me that their price on Hibiki is the lowest in the valley. I can't verify that but it was low enough for me to throw back a couple of glasses before dinner without thinking twice.
Gyu-Kaku doesn't do AYCE in Vegas (I don't think they do it in CA either) but they have some great meal plans that will bring out enough meat and veggies to where you will be full when you are done. Its more expensive than some of the Korean AYCE BBQ places, but you are paying for quality here.