I've towed with overrun brakes for 55 years and TBH I've never had a problem, and for the most of the time now I use a big 4x4. In my early years when towing a boat or caravan it was with a car and suppose I was more cautious. Now it is more heavy loads at 3500kg hence 4x4. The biggest issue with any brakes is neglect but that revolves around the actual drum pads and mechanism, which applies to electric brakes as well I suppose. I suppose it comes down to what we have been brought up and used to. If I had been using electric brakes I would no doubt swear by them, now they just see a extra hassle.