Well I think those that don't put any effort in to it will suffer, but those of us that try to avoid it will get some good mileage before it becomes an issue. People want to pretend cars don't need maintenance, and manufacturers have gotten better with it, but with GDI we have to worry about a different kind of maintenance.
As for the 109, in my experience of pulling 180k+ engines from the junkyard, you can tell which engines didn't get their oil changed at the proper intervals. Not that there was any noticeable extra wear (all have been within factory spec), but there was some extra varnish in there, but not something to worry about. Nothing like the pics you see online of the engines that never got their oil changed. Besides that, there's nothing wrong with some varnish building up. Aircraft mechanics are forbidden from removing it during rebuild time if it doesn't need to be removed from honing or some other machining process. I'm just saying, I see no reason to run an additive through the oil to keep the crank case/upper valve train so clean. Not trying to start an argument.