My personal experience is that clear lines do not lead to more hookups. I've fished pale blue intermediates next to clears for years. No dropoff. Clear lines also still cast a shadow. We all have our own experiences, but I don't see a dire need.
My experience is much like Philster's. I would use a clear floater over shallow flats with small flies, but see really little advantage in hookups. A problem is it is difficult to see on rippled water so its hard to find and follow your fly. Another idea might be a Ghost tip that increases the visibility of the line yet allows you to use a shorter tippet or increases the stealthiness of your presentation. Take a look at Cortland Ghost tip 444SL or Tarpon Plus Ghost Tip.
I have the clear Monic in WF4F. The clear does seem to help over really shy fish in very clear water on a sunny day especially. But it really only makes a difference on a longer cast (30+ feet or so). I like it and it floats and casts well, but I'm not convinced it's completely needed.