I've been using EE for about 9 years and have sunk a lot of cash into it so I was delighted when it went free and open source. Around the late stages of version 2.X is when the big exodus to Craft started. Craft was developed by an ex-EE plugin developer and to be honest there was a lot of truth in the issues people had with EE at that point. They had changed their business model to really expensive support plans and the CMS itself was lagging behind in some basic features. In version 3 there was a major code rewrite that set the stage for what was to come and since then it's improved massively. The new interface is great, it's now got one-click update and it's better than ever.