I've recently acquired the whole line-up. Only three sessions on the 6M and two on the 3M so far. Really impressed thus far.
Coming from the Swing, which started giving me serious joint pain in my fingers, the handles on the clouds are a godsend. So good! I was even able to flip the 3M over in 25mph onshore shorebreak with one hand using the LE handle while keeping my board under control in the other hand. Good stiffness through the handle and connections connections results in better control over the wing with a single hand for example.
I'm still in the process of learning tacks at this point and the clouds cross the eye of the wind and go into the wind with less resistance than the swing from my experience. This makes tacks much easier.
I had the 3.5 and 5.0 Swings. The 3M cloud had similar power to the 3.5 swing, maybe more. The second session was 14-22mph gusty conditions and once I caught a gust and got up, I was able to keep going through the lulls no problem. Armstrong 1850 wing probably helped!
I actually just took a few photos of the 5M Swing vs 5M Cloud. Here they are: