it seems to me that you grilling on too high a heat. Try the Alton Brown method. Start out with medium low heat (I’m guessing you use gas, you seem like a gas kind of guy). Cook for about 3-4 minutes a side, (yes I know I’m breaking the flip once rule) then take the burgers off (or move to a cooler spot, and crank the heat as high as it will go. Let the grate get smoking hot. Then give the burgers a quick sear (30 seconds max) and enjoy.
You could also try the old james beard trick. Mix in a tablespoon of cream for every burger you are making. add the pat of butter in the middle. You want rich and juicy? You can’r handle rich and juicy.
Oh boy… Talk about a cooked goose… I’m sitting back and watching this one!