I have only done one block swap. Very dissappointing.
Blocks were made of cheap fabric. Most blocks were not the required size, suppose to be 6 1/2 inch square (6 1/4 mostly)
The block required light, med, dark fabrics correctly placed. Some quilters didn't follow the color placement which was clearly labeled on the pattern. Out of 14 blocks I could only
use 9. I've not done another block swap.
I joined for a round robin and machine embroidered four blocks for the center of the quilt. Sent them out to the quilter. One year later I still hadn't received the quilt top. I finally called her and she sent my center blocks back.
I guess swapping just isn't for me. :D