This is the best restaurant in the Cleveland area. If you haven't been there yet then you're missing out on some truly amazing food. Every dish is prepared with great thought and care. Every flavor is thoughtfully considered and every menu item is scrutinized. Don't get too attached to anything on the menu, though, because it changes constantly for seasonality.
The "small bites" dishes are really nice for sharing (we usually order two a piece), but the "big bites" are fantastic full entrees that provide more than enough for one to eat. I had some friends go there and complain that the dishes were too small. The "small bites" are meant to be small portions that you share in order to experience a variety of food. The prices do reflect the portion sizes. If you want more, order another one. It's as simple as that. Also, note that this is not a place for meat and potatoes people. Eat at AMP 150 and be adventurous! Try new things like rabbit meat and quail eggs. If you want a plain grilled steak then this just isn't the place for you.
My single piece of advice for anyone considering going to AMP 150 is just to mentally get over the location. The restaurant is perfectly nice and refined with a contemporary, upbeat vibe, but it is in an area that's a bit run down. It's also in a Marriott that doesn't look too great on the outside (and parking can be a bit scarce) but that's quite nice inside. I've never thought that the adjoining lobby is a big deal at all. I don't know why Yelpers are so stuck on that. In my opinion, the TVs in dining areas at other restaurants are much more annoying.
I've always had great service at AMP 150 and the food consistently amazes me. Please try it if you haven't yet.