[rules-users] Are you using Drools 5 ?

Hi people, I was introduced to Drools 5 some weeks ago. And I have started to lear since. I got really excited and surprised with its amazing features and power. I really want to learn some tricks on it as soon as possible and be able to use it on one of my next projects.... I didn't test 5.0M4 version too much, just some basic rules firing.... I would like to hear from you guys that are using drools 5 about your experiences... Its safe to start a project (development starts on 4 weeks) with drools 5 on this actual stage? Anyone could tell me if the GA version will have too much structurally differences from this M4? (change public classes and methods or anything else that could generate reworks !!) Thanks for your time.... best regards Cristiano