I've had drinks with Loris Degioanni and Brendan Gregg after a conference one year (Monitorama). Getting to ask two legit heavyweights in the industry about how to monitor containers at scale was definitely a high point for me. Also, Loris is an incredibly smart and entirely reasonable guy. I grilled him pretty hard and came away with the distinct impression his tech is exceptional for what it is, and the product pretty much sells itself as a result.
I don't currently use it as we just use prometheus + kubernetes just because my company isn't big on cloud services and doesn't have a need for it just yet.
Note: I have absolutely no relationship to him or Sysdig, just am a random tech guy impressed occasionally by good tech.