As far as the refillable mug thing....POR has had only one size when we've been. There are two different styles(the travel kind that fits in the cup holder easier and the fat kind. I saw a tip on here several months ago that stated the travel one, even though it looks smaller, actually holds a little more liquid...they are the same price). I THINK one of the resorts does have a BIG refillable mug, but unsure which one. As far as it being worth the money, it depends on whether or not you'll use it everyday at least once over the course of a week or so. They run about $12 I think.
Whether you realize it or not
you have opened up a can of worms with this question. The mugs are only good for one stay and you aren't really supposed to use them on any subsequent trips, though some people do. Just be aware that the mods and the board rules won't tolerate anyone encouraging the use of mugs after your initial stay. Yep...even though these threads can sometimes run several pages, they invariably get locked up...all over the heated discussions of a plastic mug.
Whether or not you use it again is your choice, but I encourage you to not discuss it here. I'm actually betting that someone out there is already assuming you've started this thread just to raise a ruckus....and I'm only saying THAT because just the words "refillable mug" are enough to send people scattering about like little chameleons, running to hide on a leaf or under a rock. It can be ridiculous the things people wanna pick, pick, pick about.
As far as the coffee...bring your own for the in room coffee maker if you are a fanatic. I don't mind the coffee, but my coffee freako DH doesn't like it at all. It supposedly is a brewed Nescafe, but many people think it tastes like instant. As long as its not Charbuck's I'm good
.
I have only heard good things about the Kona coffee at the Poly, but you do need to go into the restaurant and be seated to get it. There is a small coffee stand outside Kona, but it's NOT Kona coffee. DH did get some a few months ago and said it was good. Also, there is a coffee shop by the elevators on the first floor of the Contemporary...DH really liked this also.
If you are eating at Boma, they also have pressed pots of coffee.