Had one on my gtd mk7.5 for a few thousand miles now with no issues at all. At first I wasn't sure it was making much difference but took it off for a couple of days while it went for an oil change and without it you could really feel the difference, it just didn't have the same urge. I run it on 2 plus 1, not played around with any more than 2 plus 2 tbh. Get about 5mpg more overall and it re-gens less. What more could you want!