We were at Heritage in mid-October and were anxious to see what took the place of Kokomo's - which happened to be a favorite of ours.  Since it was Colicchio's, we assumed it would be outstanding.  Unfortunately it wasn't.  We both ordered the filet to be cooked the same way.  While my steak was okay, my husband's was so tough he could hardly cut through it.  I gave him a bite of mine for comparison (and I had a bite of his); the difference was enormous.  The waiter did take it back and the second one was fine.  \nThe service was spotty...several \"suits\" were wandering around, then congregating at the back by the grills, talking on cell phones and looking important, while a couple of the waitstaff (a male and female) were laughing, joking, flirting and ignoring patrons.  Our waitperson was fine, as were the busboys, etc..  But the food took a long time to come, was overpriced and mediocre.  \nStack is much better, and Kokomo's was wonderful...too bad it's gone.  We won't return to Heritage, even though we stay at the Mirage three or four times a year.