I'm on my 8th mclaren with another one incoming. I track a lot, with a lot of other mclarens and other cars. Mechanical issues happen with all marques (since you mentioned viper acr (I have a friend who lemoned it), one of his issues was his rear window shattering ON THE WAY TO THE TRACK.Yeah that's what everyone says and why I still drive it with the codes, because they usually just keep disappearing and reappearing. Just to dinner and back at 45mph. But the car has me scared now to track it. Would you drive a car at 160mph on track next to a wall while thinking "Man I hope the dash doesn't pop up with another "suspension failure" heh.
I have had a suspension error but it is usually on start up and not when the car is moving. It is an error that goes away and usually has to do with how the car was started up (assuming your car has had the software updates). Car could have lifter on, you start up the car with the door open, etc., or it could just detect a certain situation and it creates the error to protect itself. That situation usually goes away upon re-start (some times it takes several minutes). It has happened to me in the paddock - I called mac service advisor from the track and he told me that another 720s at the same track day called him about two minutes earlier with the same issue. Both issues went away (was it a coincidence or something happened to both of us at the same track and at the same time and the same session?). Possible scenario is that I have aftermarket steel brakes which are heavier and this could sometimes cause the issue, non oem wheels/non oem tires, etc., can contribute to these temporary type issues.
720s is designed to protect itself and you and always errs on the side of caution with its errors. The only serious errors is when it goes limp and this is extremely, extremely rare.
My confidence level is extremely high with 720s - it is the most tracked exotic car that one will see. More and more of them are showing up at track days (8 of them at the last track day and this wasn't a dealer day or a coordinated effort by owners to show up).