5/5, sorry... I don't have a great explanation why. I think it has something to do with personal interaction. If it was over Ebay or something I wouldn't worry about giving low rating, but when I meet someone face to face and they are nice, then it's hard to rate low.
It's funny - because I've done the same thing. I've had drivers that hit the brakes way too hard, and were kind of annoyingly chatty - that I just didn't have the heart to downgrade, even though I realized that I probably hadn't had a great experience, and, they weren't the safest of drivers. But I just couldn't bring myself to give a black mark to someone who had tried so hard to be friendly.