I haven't seen a stand come with anything I would consider a decent pad for the seat or backrest. That is why I buy my own cushions. You can get all kinds of kneeling pads and such for gardening or other jobs that are much more dense that the pads that come with treestands. I have also found the compartmented foam float mats for the pool work well also.
I have found that any pads left out all year not only get dried up, deteriorated and chewed on but for some reason or another they seen to draw wasps or hornets - especially black foam pipe insulation.
My advise is that if you want something you know you can sit on all day you should try it somewhere before you have to use it in the stand.