I have tested Calypso performance some weeks ago and have not been able to write on it before. Don't use it please its fucking slow and cannot be optimized in the current architecture, because the template will NOT be parsed into intermediate PHP code.
Additionally there are some bugs:
- You cannot currently use UTF8 encoding since htmlentities deep in the escape mechanism cannot be given the utf-8 specification.
- Triple or higher inheritance may not work under some circumstances. Which sucks.
I sadly have no time currently to fix any of the issues poping up with Calypso, so please don't use it for anything production.