D rings are prone to slippage on old and dirty straps.
The only advantages I have seen in them is they work no matter how cold they get and they are cheap.
After some prolonged cleaning and decon episodes with reusable straps, I am trending towards disposables.
Roger the comment on "if it's working, you are doing it right", but caution regarding lifting and shifting vigorously without knowing what is up. Take the to do it right, but first take the time to learn it and rehearse it right.