Personally, I found this exercise to be quite helpful. My biggest problem is I tend to "tell" more than "show". Probably comes from many years of technical writing. But because I can picture the scene so clearly in my mind, it's not immediately obvious to me what I'm doing.

Having many different examples of the SAME story to compare against really helps to clarify for me what works better and what doesn't work so well. I come up with my opening, and I think it's fantastic (naturally). But then I read some of the others, and there's this revelation like "ohhhh, I see what I could've done better".