I started with CE4's but then tried a re-buildable version referred to as the Vision Ego V3 re-buildable. This I like, so am looking to get a couple more. But I have seen then advertised as Ego C5, Ego 2.0 V3, Ego V3 CE5 and CE5 replaceable. I think they are all the same but just referred to differently by the different vendors, but I would just like to make sure.