shells are nice and easy and you can buy and store a lot more of them, but fully bodies honkers look so much better and work better. We started out with all shells and over the years we have added 1-2 dozen full bodies honkers per year to our inventory. It makes a huge difference. We have been buying the tanglefree full body honkers and are very pleased with them. They are one piece and come with stick in stakes and stakes with stand for frozen or hard packed ground.
We do have full body and shell mallards dekes, but I really have not noticed a difference in their performance. If you have honker dekes out mallards will come to them.