I'm doing some heavy research on small eats for an upcoming trip to Shanghai in November, and I've been checking the composite ratings by users of dianping.com, China's biggest user-driven foodie website, of the xiaolong bao from various establishments. Ratings on dianping.com are given separately for tastiness of the food, ambience of the establishment, and service. The average tab per person is included for reference as well. For the xiaolong bao at about 120 restaurants, the highest average rating (for taste alone) was 23 for the XLB at four locales (including my favorite, Jia Jia Tang Bao). Din Tai Fung (Xin Tian Di branch) got an average rating of 19, putting it essentially in an 11-way tie for 19th place, while the original (Hong Qiao) branch got an everage rating of 17, putting it somewhere below 43rd place.
I'll post a list of the top 10 or 20 once I translate the essential details. I hope to check out at least the top 10 myself, though I'll have a few other fish to fry and dumplings to munch on while I'm there.