Being entangled is not too bad, and it is almost worthless depending on the foes damage output, hardness 10 and 12 hp is not that much on foes when you can afford this item.
And entagled does not prevent flight. It might slow the critter down a tad. And if someone is holding onto the rope, they will soon by flying the unfriendly skies...
Entangled
The character is ensnared. Being entangled impedes movement, but does not entirely prevent it unless the bonds are anchored to an immobile object or tethered by an opposing force. An entangled creature moves at half speed, cannot run or charge, and takes a -2 penalty on all attack rolls and a -4 penalty to Dexterity. An entangled character who attempts to cast a spell must make a Concentration check (DC 15 + the spell’s level) or lose the spell.
Rope of Entanglement
A rope of entanglement looks just like any other hempen rope about 30 feet long. Upon command, the rope lashes forward 20 feet or upward 10 feet to entangle a victim. An entangled creature can break free with a DC 20 Strength check or a DC 20 Escape Artist check.
The rope has AC 22, 12 hit points, and hardness 10, and it has damage reduction 5/slashing as well. The rope repairs damage to itself at a rate of 1 point per 5 minutes, but if a rope of entanglement is severed (all 12 hit points lost to damage), it is destroyed.
Moderate transmutation; CL 12th; Craft Wondrous Item, animate objects, animate rope, entangle; Price 21,000 gp; Weight 5 lb.