I looked at all my hives yesterday. I found all five of my queens and saw nice solid laying patterns - large patches of cells completely filled with eggs and larvae. They had stored syrup in both the newly drawn comb on the plastic foundation, and in the drawn comb I'd given them. I'll continue feeding - the dandelions have not bloomed very much yet.
All the new hives looked prosperous, with new cells drawn on the plastic sheets. I have seen the light: I love the plastic foundation sheets. The bees go right to work on them. They save a lot of time futzing around stringing wire and embedding pure wax foundation.
Today I'll remove the restrictions at the openings of my hives.
I look forward to reading your comments - I'd like to hear of your experiences of looking into your hives.