Most onboarding checklists are built around what has to happen: contract sent, invoice paid, kickoff scheduled, files shared. Check every box and the process reads as done. But “done” and “felt good” aren't the same measurement. 

But 'no complaints' isn't the same as no one struggling with your onboarding process and just not saying anything. The person who abandoned your inquiry form half way through, didn't complain. Neither did the person who was overwhelmed with the 40 open calendar slots (and silently closed the tab).