Safari 9 on Mavericks

[Labhras]

Hi all,
I'm currently running Mavericks 10.9.5 - I saw the Safari 9 update for Mavericks, but I've read mixed reviews.
People unable to turn off all the extensions - as you can do on Safari 7, complaining about slow software, or taking too much CPU, or problems with watching videos on webpages.

Before updating I wanted to know if those, in your opinion, are rare cases or are common problems for this update on Mavericks?

Thanks for your help

 

[Pearl Wisdom]

I'm using Safari 9.0 with Mavericks 10.9.5 and have not had any particular problems. There is still a master switch to disable all Safari extensions.