The Dazu Rock Carvings are amongst my favorite WHS in China! When I was for business in Beijing last year I decided to fly to Chongqing to visit 2 WHS (the other Wulong). I did a day trip to the Dazu Rock Carvings.
I was amazed by the beautiful colors especially at Baodingshan and the fine carvings at Beishan. I think they are much nicer as those at Yungang and Longmen. I visited 4 out of 5 locations as I left Chongqing to late in the morning. I didn't see Shizhuanshan which I regret a bit as that's the one where really each 3 religions are present. Baodingshan and Beishan are full of tourists but at Nanshan and Shimenshan I was alone.
Dazu isn't included on many standard China itineraries but if you have the option do go. These carvings, thousands, are a true wonder. I would even compare them with the Terra Cotty army. Which is also amazing.