One of the things we've added to our product line at Malu Marine is rope compensators. With rope compensators there are two basic approaches: metal spring and rubber with rope wrapped around. We've put the new ones on the stern lines for a few weeks now and been very happy with them and the one from the pole to the cleat amidships was one of the earlier ones.
The normal problem with the rubber and rope wrapped is that it's difficult to put them on as you have to thread the rope through the compensator eyes.
The new ones have shackle ends so you can very easily put the rope into them. You can see the two different styles here.
The reason that there are two, an old style and new on the pole is that the old style was also too light duty for our 15 tonne boat (Nicholson 39) whereas the new ones will cope with the weight under surge much better.
You can see how different on this photo where the boat is being pushed back on a surge.
