prestashop 9 is cool and awesome with nice admin look and some new features but as the dev advices to use on stage site first to try out all features and functions
If you do new site - better using new version. I am thinking to try version 9. But problems with modules. You should understand modules you haven't enough at that time...
Post automatically merged:
If you create a new website it will be much better to use a new version. I plan to try the Presta version 9. But there are issues with modules compatibility at this time...