Regardless of whether or not you like good service, it is irrefutable that Szchewan Palace serves authentic Szechuan cuisine.
Food:
My parents are much more aware of the places to eat Chinese food in the Phoenix area. It is well known among all their friends and themselves that the chef here is one of the more talented chefs in Szechuan cuisine. He knows how to cook and he cooks well. Whether or not you like the food is probably more of a preference for this style of cooking (if you're ordering from the non-Americanized menu). We ordered Xi Long Bao, Fried Fish Fillets in Chili Peppers, Beef Tendon in Spicy Oil and Peppercorns, and Dried Tofu with Pork Slice & Celery. The Beef Tendon in Spicy Oil is what they are famous for and it was good. It is an acquired taste so that dish is not for everyone. The Xi Long Bao wasn't as thick skinned as a previous review had mentioned. They may have changed it since that review.
Service:
I know this place gets a lot of heat for their poor service but our experience was 180 degrees. We were served by at least 3-4 different people and they were all very friendly. It may have been because my parents spoke Chinese or it may have been a different set of expectations. Chinese restaurants, in my experience, vary largely on their service because that's not what you come into a restaurant for - its for the food. If having good service is a critical component of your dining experience, I'd say this may not be the place for you. We did get our food almost within 5 minutes of ordering and our waters were refilled frequently throughout the dinner.