The platform allows us as an agency brand manager at our firm do what we were hired for - manage client brands in real time! This has been great because it's allowed me more freedom than managing my own clients would have given (and I've had many).
It can be slow loading sometimes but that seems like most any other web application these days so not much different from using another app or website where you're also logging into multiple accounts simultaneously anyway? We use this tool both internally within PM team members who are working together across projects/initiatives AND externally when providing services via proofing engagements.