I stayed at the Shamrock a couple of times...it didn't seem too bad, but like someone else said, that was a long time ago. I don't know what time of the week you'll be there, but if possible, I recommend going on a Sunday. My wife and I went yesterday and it really was not crowded at all. There were virtually no lines at all on a lot of the rides (Black Thunder, Point of No Return especially) and manageable lines on the more popular rides like Black Anaconda and Time Warp. Plus, the Noah's Ark website has a $5 off coupon for Sundays too. Just Click on "Promotions"