[B8FISH]

I'll take a shot at it--may not be 100% accurate. The 7Iron decks are made from thicker steel and may have higher blade tip speeds. The drive over decks (usually the width with a D at the end) are pretty nice--especially if you don't have a lot of room for storage--you can drop the deck and leave it in place while you go off and connect another/different implement. I don't know the difference between the B and C decks--maybe based on what machine they go on. The non drive over decks are not hard to maneuver around--just rotate the wheels 90 degrees before you drop the deck and roll it out--only easy if you have a relatively flat surface to work on--it's a pain in the lawn!