I like that it is easy to use, has very good documentation for beginners as well experts alike! It's not free but what do you expect when your using Open Source software? You get features at no cost with any license other than GPL v3 or Apache License 2 which are both great licenses in my opinion so don't let price be something holding back from trying this out if its available where ever u r going too! If i had anything negative about hibernation would have been lack of support/documentation resources during initial setup phase - however they seem pretty active now though still need more docs especially around how we can make our own customizations / plugins etc We've used ORM frameworks before such SQLAlchemy (python) & ActiveRecord(Ruby). But found ourselves constantly having issues understanding why things werent working right sometimes even after reading their documentations over multiple times So far all problems solved by searching online forums here :).