That's good to hear about the Sigma. I have always wanted to try them. For all intents and purposes, I have heard they are just beautiful. I will definitely pick some up down the road. I hear you about the autofocus on it. It's incredible how well it works. I also found continuous AF wasn't the best, but single auto mode works brilliantly. It honestly looks like someone is pulling focus with just a little tap on the screen. And it locks on whatever you choose 95% of the time in a way that is actually cinematic like a good focus puller would. Now, I think for most cinematic film shoots, having a focus puller is probably the best way to go - but if you are in a pinch, it is quite stunning what the lens can do.