That intermediate tip would be great for the flats. You can pick it up quickly to make casts to moving fish. I would venture to say that the scenario that you describe in lakes might be more suitable for a floater and a weedles fly. You could use the sink tip for submerged weedbeds. I can say that from fishing lakes for trout and large weedbeds. I use the floating line even when making subsurface presentations especially when fishing along shorelines.
I hope this helps you out.