Does anybody have an experience with it? Could you tell me about it's advantages and lacks?

Its one of the most mature php framework out there...a bit bulky though...but worth it...
if you google you will get so many comparison and benchmarking articles about php frameworks...check how zend framework fairs with them...

You're questions are quite broad and general; you're going to be better off using Google and the Search Forums feature - as well as checking out programming forums - to find a reliable and well thought out answer.
Personally; I like the Zend framework, however for all of my projects I've found it to be over-kill and therefore it has impacted negatively on my application's speed. It's pretty large and so can become a bit slow if you don't use it carefully. :)
That said, I would use it if I needed all the features and if the hardware it was running on was suited to handle it.
Hope that helps,

If you like MVC it's okay, but if you're not used to it, you need to pick up a book and read up on things.

it's good as long as you take care while using it