Yes. I can confirm. However.
First the bad news:
* Drupal7 core is more complex. Complexity costs performance.
* Drupal7 core is bigger: more features, more in core. **more** equals **slower**.
Then the theory:
* In Drupal6, approx. 95% of the projects included CCK. Call that Drupal+. Drupal7 comes with CCK out of the box. Drupal6+ is **slower** then Drupal7.
* Drupal7 offers a lot of enterpris-ish abilities for performance tuning. Memcached, (Varnished)Proxy support, Database balancing (master/slave etc). Something that Drupal6 could not do.
However, [Drupal6 pressflow had these enterprise-ish things build](
[To see links please register here]
) in (in fact: these pressflow features made it into core, offering the basis for Drupal7).
[Drupal7 is slower then Pressflow Drupal6](
[To see links please register here]
). Drupal7 offers performance features that Drupal6 did not offer, but that PressflowDrupal6 did offer.
Many projects also have views module enabled. Views3 in Drupal7 offer a lot of performance improvements (enterprise-ish features) over Views2 for Drupal6.
My advice: untill there is a performance-optimised Drupal7 (Pressflow Drupal7, for example) Just stay with your Pressflow Drupal 6. It is in both theory and practice a lot faster.
If you can benefit from the Views3 improvements and features, then go for Drupal7+views3, that will give you more options to tune performanceissues.