I never had a problem with my retic. It was a pretty hardy ray and ate well.
But that's not all that makes a good beginner's ray...availabilty and price do as well. i understand that other rays may be hardier than the retic, such as the leopoldi...but they are by no means readily available and incredibly expensive.
But I never said anywhere that they make really good beginner's rays...i said fairly good implying that there are hardier rays out there, but I did not reccomend them to a beginning fish keeper.