I was the lead developer behind the recently relaunched American Diabetes Association - http://forecast.diabetes.org/ - rebuild in Drupal. At launch, we were getting about 250k uniques/month and it's been growing significantly. While the criticism for "inefficient query chains" is mostly accurate, there is a reason for that. The Lazy Loading pattern is used as frequently and often as possible. To streamline the process a bit, you can always configure Drupal's caching, there are some addon modules, and then you could go with something like APC or memcached.
Regardless, the trade off of being easily extended, customized, and - in normally less than an hour - having something to show the customer and allow them to load content, is pretty significant.
