You can get 2-3 ms response time (sans network) with any of Django, Flask and Pyramid. Database queries tend to eat a lot, esp. if the queries are bad (long wait in the DBMS or post-filtering in Python/whichever); sometimes ORMs can eat a fair bit as well. But it's fairly rare to get that low, most pages for me (that I cared about) will take 10-30 ms. Using the correct tools and the right approach is fruitful as always.