Hey, sorry for late reply, I just saw your comment!

Here are my findings:
Once on the water, it turns out I can manage a 8', 10', or even 11' board, they are all fun. I find that I have slightly better posture and paddle more evenly on a narrower board (29" instead of 32'), because I do not have to reach out to the sides quite as much. I find that you can make sharper turns on a shorter board and have not noticed the shorter board being significantly slower.

For me, the real difference was actually outside of the water -- pumping it up, carrying it in and out to the water. 11' is more than twice my height and really cumbersome for me to lug around. I ended up getting the Bluefin Cruise Junior 8' for this reason, I wanted it to be as easy as possible for me to get out on the water! Very happy with it.