I think the only downside to rip-rap is walking on it barefoot. As mentioned, placed to about 4' below low water points, it can discourage/eliminate muskrat and nutria damage to the pond. Adding Limestone rip/rap will also help buffer natural acids produced in the water (granite won't), greatly reduces erosion from wind/wave action, provides great forage species habitat (like crawfish, reptiles and invertebrates)....personally, when done well, I think it looks great too!