The link is not working. When I bought mine new it was rolled up and unrolled with no problem. There is a big difference between rolled up properly and tangled. Tangled is probably do able but they are so heavy it is a HUGE PITA to do.
I keep mine rolled up for storage, and transport, as I don't have a frame to carry it with. If you roll them up nicely, they unroll just as nicely. If it's tangled, it will take a bit more effort. But once it's open, just be good about rolling it back up instead of just tossing it into a pile.
Its good to know that if I untangle it and reroll it correctly then it won't be a hassle each time. Providing of course, that I make the purchase. They are asking $150 so if its a lot of work maybe it won't be worth the asking price.