It's used for decking on boats for a good reason - very weather resistant, pliable, easy to walk on and insect resistant.

And, if stained and varnished, can be beautiful.

The floors both inside and outside of my boat are teak. The inside floors are gorgeous. Extra added bonus, they are really easy to clean.

i think if it were me, i'd look into putting heating mesh into a stamped, colored concrete floor

the things they can do with concrete these days is amazing! i'm not sure the heating mesh you can buy for tile can be used in concrete, but i'd sure look into it.

otherwise, go with tile is my suggestion

edit to add links http://www.servicemagic.com/article.show.Concrete-Floors-Solid-as-a-Rock.14332.html

http://www.essortment.com/ideas-concrete-floor-treatments-14347.html

http://www.concretenetwork.com/concrete/interiorfloors/common-questions/cold-damp.html

because they don't tend to suffer much from temperature changes.

Eventually, though, any floor you put down will fail if the only thing you have on top of soil is tar paper and plywood. What you need to do, really, is have a concrete floor poured over the tarpaper. Then you can put the tile on top of the concrete once it cures and it will be stable. The tar paper will keep it relatively waterproof.

If I were doing a temporary floor over the kludge plywood/tarpaper floor, I'd do cheap laminate since that floor is going to fail sooner rather than later.

The subfloor is not right down on the soil. It's up on joists set on concrete footers.

out of the boards as they lay them then they walk around with a woden mallet and hammer the knots back into the holes once they are done. Really nice and dark. Warms up a room.

Google that phrase and you'll see a lot of options. I think it will meet all your needs.

It looks and even feels like wood (on its surface), so it is nice and warm.

It is easy to install.

It is widely used, in the heavier gauges, in commercial applications, like department stores.

It is waterproof.

It will no doubt do fine in your three season room.

wore like iron (we only had to replace 3 planks in front of the dog door to sell after 7 years)

I noticed the big box stores had it in stock these days, we got ours as a special purchase from Costco over 15 years ago.

what's funny is that our PHX house got repo'd after we left and listed for sale last year (5 years after i left) it still had the same floors in the realtor pic

. . . . . . the vinyl planks. We may still do it.

I am curious, and in need of a new floor.

...but I have to agree on the vinyl plank flooring.

Inexpensive.

Easy to install.

Waterproof.

Looks and feels great.

As far as I am concerned, for practical, relatively inexpensive flooring, it just doesn't get any better than this.

I did my whole first floor last year, and I'm doing the upstairs bedrooms now.

You've given us things to consider.