Hi, i'm sorry by the delay in replying, but we have not received the forum notification for your post.
Replying to your question, the problem here is the spherical UV mapping, which has not the same scale along the sphere. You can see how the UV coordinates are deformed using a Checker map.
I've been running some tests, and i got the best results with these parameters:
Distribution map Full
Collisions on, radius 50%
Transform Translation X: 20%, Y: 20%
Transform Rotation: Z: 0 to 359º
You can also try applying a box mapping instead the spherical one. The geospheres seem to generate a more uniform result as well.