I generally eat dim sum at Phoenix Palace as I have found the regular menu items to be better in other Chandler restaurants. Love the online ordering option though, very convenient.
I grew up in SoCal near Monterey Park and Hacienda Heights and I definitely need a dim sum fix a few times a year. The offerings are at Phoenix Palace are surprisingly similar to those of CA dim sum restaurants. Chicken feet, porridge, crispy taro puffs, egg tarts, spare ribs, steamed stuffed rice noodles, bbq pork buns, etc are all offered via push carts. The quality is pretty decent, the wait staff speak cantonese and its generally an authentic experience.
I prefer Phoenix Palace as opposed to the other large restaurant across the street also offering dim sum. The food is fresher (perhaps due to larger turnover). It certainly gets busy on the weekends and the general rule of dim sum dining is to arrive before noon.