We purchased the king-size chair (and bed protector) and footstool 3 days ago and it is already the most popular seat in the house! We've had kids belly flopping into it, rolling it around, and we've already used it for a sleepover. We bought the espresso chenille cover and it seems very durable and is extremely cozy as well. I can't wait to curl up in this chair in front of our fireplace this winter!
I went into the store thinking I would buy a queen-size based on the reviews, but the king size is roomier -- in the queen-size, if I sat with one of my kids, we had to want to be quite cuddly. In the king-size, we have a bit of space (although not alot - it would be cozy seating for two adults, I think). We wanted extra seating for the family room and also needed a guest bed. So far this has worked wonderfully for both.
I would definitely recommend purchasing the footstool, as it changes how you use the chair. With the footstool, it's like a recliner and I can definitely see taking naps there. My only complaint about the footstool is that it seems quite understuffed for a footstool (more like a pillow), so I may need to order a booster pack to firm it up a bit.
Fair warning - it is a pretty big chair, so make sure you have the space for it. They look bigger at home than in the store - that's true of any of the sizes.