When fishing eggs I use the mcfly foam much more versus the otter eggs. It may be the way I'm tying them up, but those otter eggs seem to have a serious durability issue after a couple fish... The preventative measure for this is to make a few wraps in front of the egg and then go over it, make a few wraps and then go back over to finish the fly. Even after doing that, they just don't seem to hold up as well. On a sunnier day, I think the otter eggs may tend to work better, especially with clearer water, but if not then I stick with the foam eggs. To be honest I haven't seen a huge difference in catch rate between the two. I was using a double egg rig a few times this fall with one of each, and the fish didn't seem too partial to one or the other.