Owlbait,
I only open the windows on one side so the deer can't see my outline. I don't have to swivel all that much -- but I have found that being able to quietly swivel is important. I have used a little wooden stool with a cloth on top of it so I could quietly swivel my butt. I have also used a quiet swivel chair with a back. With the chair I can take a nap if things are slow. Both work really well.
I am considering one of those swivel tops for a 5 gallon bucket. It would provide some storage for bottled water, etc.
If you get one, you will like it.
Joe