We have had one for almost 2 years. Got it in Nevada at Lowes for $99.
Love it. No smell, no smoke, no firewood, and can use it during a burn ban. Best thing, is when you turn it off, it's off. No embers. Go inside to eat dinner and turn it off.
Gives out an amazing amount of heat for its size. A 20lb or 5 gal lasts usually lasts us a week of nightly use. It depends how high you turn it, and how long you use it a night.
We have several people a week comment about getting one, and they come over and share our fire sometimes over cocktails.
One of the best investments we have made since we left for fulltiming almost 3 years ago.
We get propane for under $2 a gal, so for us, it's a no brainer.
Edit....As for your marshmallows, it will stink until it's totally burned, but we have dropped a couple items on our lava rocks, and haven't had any problems.