My close friend who I came here with grew up in Hunan Province (neighboring province with somewhat similar to cuisine to Sichuan) and I lived in China for 2 years. I think I speak with some credibility when I say this is one of the few outstanding and authentic Chinese restaurants I have been to in the US. If you are not familiar with real Chinese food, come here and order something you've never had before. Frankly it's better than most good restaurants in China.
On the other hand, it seems more Hunan than Sichuan, since I didn't taste much huajiao (the stuff that makes your tongue tingle), but I've barely found anywhere that cooks with that in the US. That's not necessarily a bad thing though.
Don't be put off by the decor. It's classic China. And there is a general rule in China that the crappier the hole-in-the-wall, the tastier the food. This place is no dump, but it might be a bit too Chinese for most Americans.