Isabella and I actually started as pen pals, just discussing random things, sharing thoughts on different topics of all kinds. As such, my perspective is going to be a bit different since I didn't even think she'd be interested in me as a story partner. Still, as a person, she is intelligent, she is kind, she is generous, and she is willing to listen, which is a rare treat to find (I know I suck as a listener).
As a writer, her characters feel absolutely real, and she is very dynamic in how she'll respond to a situation. Our story, DeD_RunnerZ, did not have planning behind it. We had a basic idea and decided to just improvise it. With each post, we each began to fill out the background more, revealing bit by bit to one another, and it continues to evolve in ways we did not anticipate.
I could not have hoped for a better partner on this platform. But, I must warn, I rate her five stars because she is best in class in writing capability, description, and character. You have to be up to the challenge, but if you're able to put in that extra effort, the reward you'll get is great.