I'm going to disagree a little bit. I'm playing some Diaspora right now, but with FC aspects and it feels a bit limiting. Diaspora has a lot of skills. When you take those out, you're really going to change the feel of the game- so tread carefully. 5 aspects is too few, 10 is probably too many- 7 might be a good sweet spot.
Also, stunts in Diaspora are weaker and more constrained than FAE.