I have never unrolled hay, so I cannot comment on that. We started with the metal feeders and they were bent up, rusted and shot in approx 5 years. Since then we have used only the poly, and I would never go back to steel.
The trick with the poly is to put in additional spacers, that we be 2 spacers between each support post. This helps alleviate some of the climbing into the feeders. You will still get an occassional smaller animal in.
The second trick is to every year check all the bolts that hold the posts together,they get bent or broke off. Once I learned these two things, I have not had a complaint.
If it were me, I would buy them at $75, it'll cost another $75 to put the spacers in if you so choose.
One other item I will mention is that we have the 9' feeders so we are able to put 3 of our round bales into each feeder on end, and we have 4 feeders, usually this will feed out our animals for a week at a stretch during the coldest of months.
Michele