I use an Eastman "Ice Cube" 4 man shack.....Good Points: Huge amount of space inside. Very lightweight. Comes in it's own carry bag with 4 ice anchors. Found two faults: 1. Zipper is too lightweight and breaks easily. 2. The skirt has a tendency to freeze to the ice, making take-down difficult.
If you want something that sets up in 30 seconds, this is the way to go. Very comfy to fish in!!