I've never owned, or even used, any kamado style cooker, but I'm with Al...my guru is the bomb in my gravity fed charcoal cooker! It works so well, I've gotten pretty spoiled. Once it gets to up temp, I just don't have to worry about it after that. As long as I don't let the cooker run out of fuel, I know the guru will keep a rock steady temp for as long as I want it to. I'll just bet it's the same in any kind of ceramic cooker too!
I have the BBQ Guru CyberQ WiFi and I use it on both my Kamado Joe Big Joe and my Akorn. I am very happy with it and often just use it for temp monitoring, due to the WiFi capability. It is great to be able to do long overnight cooks and not loose any sleep. Your Vision is fairly good a maintaining temps and I don't feel a controller is absolutely necessary with a ceramic kamado style grill. It is very nice to have though and I wouldn't give mine up for anything.