My honest opinion about cloud AVs, a waste of time.
We have got by for so long without cloud AVs, I'm sure we can protect our systems just fine without it. Some cloud AVs aren't too compatible, others whilst they might be compatible are still using system resources as everything isn't on/in the cloud.
One such example has a download size of over 70MB and that's bigger than avast. I also don't believe they have reached anything like maturity yet.