I thought this was an interesting post because I had thought about posting same myself. My findings in zone 5 garden is that there are ones that don't open well on cool mornings, and if they don't start out opening well, then they finish crappy as well even as the day warms. It seems that there are more of those than ones that start out opening slowly then finish well. [That's why I'm in the house instead of in the garden. I enjoy cool mornings, but not so much cool and wet.]
I have to say in my garden, Last Snowflake has been about the best for opening well and looking good on cool mornings. It's seedlings seem to carry on the same tendency. I was also surprised that HIllbilly Heart has been opening well, even with shade until about 10:00 or so.
