For my commuter, the plastic toe clip with double guide loop for the strap is really the best IMHO. It is rugged, doesn't rust, and keeps the opening very big for easy entry. I am usually wearing old jogging shoes for commute, so the wide opening is important. For rainy days, I use Vaude brand nylon gaitors/rain booties. I need the opening real big to make sure I can get in, but also get out without them snagging.
For vintage road bikes, I use metal clips. Steel is definitely more convenient. I have one set of the lightweight alloy type with single guide for strap, and they are very flimsy. I often have trouble getting into those, and miss the first or even second attempt. Those are on a set of MKS Esquartz pedals with the flat toe clip mounting scheme.