Here’s another example of a version change. As you can see below the Hurricane 10 is much shallower or as I prefer to describe it more fitted than the 9.
It’s also got a more proportional toe box, so if your heel to ball is sized 8 and your heel to toe is sized 8, your foot will fit nicely in this shoe. On the other hand if your heel to ball is an 8 and your heel to toe is a 7, you’ll do better in the Hurricane 9 as the Hurricane 10 may have too much toe box room.
Now let’s look at the width.
The Hurricane 10 is slightly more tapered on the inside which is good if you have a narrow foot. On the other hand, the Hurricane 9 is much boxier over the instep and arch, typically better for a wider foot.
Also notice the flex grooves. The Hurricane 9 is going to be more flexible in the forefoot, due to the grooves going fully across the forefoot. The Hurricane 10 is going to be less flexible. What does this mean? If you get ball of the foot pain you’ll probably be better off with the 10.
Since the Hurricane 9 is on it’s way out, if this is a good fit for you, then the 10 probably won’t be. However, it you haven’t tried the 10, then this is a great shoe for a lower volume foot.
Dr. Jenny Sanders Shoe Blog 
Everything in the article above is completely true. I’ve used the Hurricane 9 for 5 years and it took testing about 10 pairs of sneakers to finally find that shoe…the perfect solution for my feet. Now that they’ve made changes in the 10 my foot doesn’t work with the 10 so I’m on my search again for a sneaker that works. I’m testing my 11 pair of shoes today…..so far can’t find anything that fits the way the 9 did. Why did they change a good thing that worked!!! frustrated!!!!!!!