[spdionis]

And Magento is slow for a whole lot of reasons, nine of which are related to symfony.

[AMHOL]

Magento is slow because it uses EAV

[oafitupa]

You mean the first version of Symfony (Symfony 1, which was monolithic like Rails), and not the current Symfony (Symfony 2/3) which has nothing to do with the old one other than the name.