Earlier quoted context omitted.
Actually, I do make French Laundry food at home sometimes. From the original cookbook, anyway. I would think you still need something vaguely vacuum-sealer-like, since as the Baldwin guide says any air pockets will expand and insulate half the object. But I suppose I'll try the $40 vacuum sealer.
You definitely get small pockets of air. On the other hand, the week I started doing this, I fanatically probed the temperatures of the proteins I cooked, and they were invariably exactly where I set the controller to. It got boring, so I stopped checking. Also, the difference between perfect 131-133f ribeye and carefully cooked conventional ribeye is not subtle .
I would imagine that the pockets of air is going to matter less the longer you have the protein in the bath. What is your typical use case start it in the morning before work and then dinner? or is is a more abbreviated cycle?