Hibernate 3.x vs 4.x performance perspective

Question

Is there is any differences in the performance between hibernate 3.x and 4.x ? and what is recommended to use (i mean is hibernate 4.x is stable)

Answer 1

Since Hibernate 4.x has been release a while ago (2011) it can be already seen as stable.

This question highlights what is new/improvements about Hibernate 4 and this website makes a comparison between versions 3 and 4 presenting the improvements made in each release.