Sudden thread revival time!

I'm designing a new robot for our team's offseason events and have been interested in the square hopper design. I know 11 used it with success and a number of my friends prototyped it and it worked well for them as well. In the 2013 season we used a bucket and, while it "worked", it bent a lot and got pretty beaten up. I believe a strong, aluminum square hopper would pose little problems, though this thread has lots of people saying their square buckets didn't work.

Now that the season is over, what is your opinion on square buckets? Has anyone who tried them had problems? If so, please describe the problems, and indicate whether the problems could have been attributed to another part of your robot rather than your square hopper, since that is a factor.