I looked both up on hmf, but was curious about the opinion of someone who grew both. Summer Song sounds like a major improvement. I have Crown Princess Margaretta (possibly mispelled) against a trellis. This is its first season, I need to grow it longer to comment. The blooms are pretty, but smaller and more pale than expected. My favorite Austin so far is Wildeve. It is not a fair comparison, however, because Wildeve is my oldest rose and sentimental favorite as "the first that survived the winter".
