Absolutely outstanding.
I dream of reasons to go to Cleveland simply to visit this restaurant. I'm not kidding. This is simply the best SE Asian food I've ever eaten- and if you look at my reviews, I've eaten at many SE Asian food joints in many geographic areas. Other places may have one or two dishes that may be better, but overall this place is the standard by which all other Thai and Cambodian restaurants are judged (and found wanting).
I always get their homemade Tofu in the dishes and it is outstanding whether in the Loath Chha or Kuy Tev Chha Khmer or just plain fried as an appetizer. My husband swears by their Pad Thai. It was the first thing he tried there and finds it so delicious (and our visits to Cleveland so rare) that he refuses to try anything else on the menu, as the torture of knowing such delicious food in one place exists is too much of an exquisite torture.
If you are in Cleveland, go to Phnom Penh. If you've never had Cambodian or Thai, the servers are friendly and willing to talk you through the menu. The food isn't Americanized, which is absolutely a win in my book.
When you go though, make sure you bring cash because Phnom Penh does NOT accept credit cards. Now, what are you waiting for- go try Phnom Penh!