I think that they are a must (at least in my family!). I usually just get the manufacturer's door edge guards...however, they are pretty expensive! My Sienna's front door edge guards are over $100...for just two doors! Apparently, they are expensive because they come in your factory color.
I don't use them. IMHO, they're nice when new and ugly when it fades or start peeling off. Plus, I open my door carefully and slowly. But everyone has their own point of views so.
Scotchgard Paint Protection Film - Door Edge Guard by 3M
Try using, Scotchgard Paint Protection Film - Door Edge Guard by 3M.
clear door edge guards that i've been using for 4 years on all my cars. its much better than those fat door edge guards that stick out and ruin the body lines.