The Rustoleum, if you do some homework, is not made to be a stain at all. Its for decks that beyond power washing and staining, but still have life left. If the deck is decent, power wash and restain. If its at the end of that life and the wood is wearing, buy it.
As for the bad reviews, and as pointed out, 99% of the bad reviews are because folks do not read, assume, nor follow every direction. There is prep work needed, and specific conditions and drying time. Mess one up and it fails, whose fault is it? Most will blame the product....when its the idiot with the product.
It works, but you need to follow directions. It will be a "textured" surface and is not feet friendly for long periods of time. It will last if done right, and put down with appropriate tools. I have painted and hired painters. If you use a roller at my house, it better be new. I don't want to hear your story or anything else on why your roller is so great and can be used a hundred times. BS- after one use the fibers are damaged. If you can't afford a $10 roller or learn to bill it in appropriately, you should not be in business. If you use this stuff, buy a good roller......and not one you will find a box store...your paint store! You will see a huge difference. Also double the dry time before walking. We did my sisters deck, ensuring everything was followed, doubled the drying time, and the stuff is doing an incredible job, even with dogs and kids all over it.