The Cloud vs Sub thing is going to get asked a lot, so we might as well address it. Quite frankly, it's a big compliment to be in that comparison, so well done already for the Sub.
The short answer from me is it depends on how you want to hit your medicine. After having a Cloud for a couple of years and the Sub for a couple of weeks, I think they are very comparable in extraction. they both hit hard and are efficient. They are my two biggest hitters. But they are very different and built for different purposes. The Cloud was designed to give the purest, tastiest, biggest hit and to replicate the bong hitting experience for heavy smokers...and it does it very well. The Sub was built to replicate and refine the dabbing experience...and it does it very well. It can use herbs to mimic the quick one hitter experience of dabbing, and is a groundbreaking design.
If you are a dabber or use a lot of concentrates, or if you are already comfortable with using a nail, then the Sub is probably down your alley. If you are a flowers only person and don't like dealing with hot objects, then the Cloud is probably for you. Both vapes produce fantastic vapor, so it becomes a usage question for me. You can't go wrong with either one, luckily.