Just wanted to share this performance tip.
We are running reports, which were actually not running that impressively fast from our website.
The initial load was very long, and subsequent request (which I guess it reads from the FileStorage cache), was ofcourse faster.
We then added a SSD disk to the dev server, and in the reports controller code we changed the path to the FileStorage part of the ReportServiceConfiguration, so it now pointed to a temp dir on the new SSD - and it now runs 10-15 times faster :
After the first request, changing pages or reloading the report takes 1-2 seconds - before that it was 20+ seconds.
And this is just a dev server, and the SSD was added via USB2 - so I am sure we can make it run much faster when we put it into deployment on bigger hardware.
Hope it helps some fellow Report developers out there ;-)