I have mostly the traditional tempered sheet metal ones like this :
MKS Steel Toe Clips from BikeBling.com..
what I do to improve the nylon webbing of the commonly available toe strap is saturate it with Plastidip, the tool handle stuff..
Coatings and Adhesives, Rubber and Plastic Coatings | Plasti Dip Interntional
that stiffens the nylon to stay open and circular, more like thick Leather toe straps did .