I migrated a site for my client from SS v2.4.5 to v3.0.3, but the site is tooo slow on the same hardware (dedicated hosting). The new version is slower 3-6x dependent on page type. For example, when a page with "Page" page type is loaded it's 3x slower (there are 10 pages with "Page" page type) and when a page of "BlogPost" page type is loaded it's 6x slower (there are around 300 pages of "BlogPost" page type).
Consider that there are not any modules installed (except Translatable in v3) and no additional logic was added. Also, there are not any complex query, only the core logic for displaying pages and page holders.
The website is bilingual and the only difference is that Translatable is now installed as a module and not part of core SS installation.
Have you experienced similar issues with SS v3.0.x?