I like the machined eyes that have the flat end that allow you to stick on reflective eyes. Orvis makes them as well as another company( I like the other company but can't remember the name, they are much cheaper). They get the fly down and seem to have held up longer than the lead ones. I also like to put a bit of epoxy over the reflective part and the head of the clouser. This adds depth to the appearance of the eye as well as adding a little bit of durability. Still repeated pounding on the rocks will take a toll but I have found these seem to last longer.
John