Tandem dolly experience

I have a Tandem Tow Dolly I just bought it last month and only have one trip on it so far. I can say that the bike loads every easy and I did not notice any difference towing. We had a Kar Kaddy SS before I really like being able to take either our bike or Golf cart with us. I bought the 4 foot bed because I am only going to take one bike or a golf cart and I did not want the dolly to be any longer that in had to be because of space in some campsites. The only problem I am having with it is deciding what kind of trailer lock to use on it. The brakes are so big the cable through the wheel to frame will not work. I just don't think the $19 Wall Mart hitch lock would slow anyone down and at some events it may be a little too tempting setting unlocked.