You are talking about apples and oranges when you mention Cook's found here
and Calphalon. My answer is get both and use for different reasons. There's nothing like a big, heavy Dutch oven. As you can see in the link Lodge also offers one that is pre-seasoned also. Sorry, I'm a tried n' true kinda gal and would have to go with Lodge.
But if the coupon you have is for Cook's then I feel sure it will be fine and last past our lifetime!
The Calphalon you are referring to I would imagine is the enameled cast iron? Enameled cast iron is still a different creature. I would save your calphalon coupon and just get a different enameled cast iron vessel - like the rectangular baker. I like to heat that up super hot, brown a pork roast, and then finish in a very hot oven for about 25 minutes.