I prefer to sew with someone and not collaborate on a quilt. I did a round robin years ago and one of the gals paper pieced some lovely blocks but her stitches were too long (like basting stitches) and the seams were unraveling with the paper still attached (I was taught to stay stitch a scant 1/8" around my paper piecing and use small stitches). I had to take her blocks apart and re-sew the seams.
I did a block exchange and we were all given one fabric to use and were told to make a 12" star block of some kind. Well... not everyone did a star block and not everyone used the starting fabric and the blocks ranged in size from 10" to 15". I won the blocks (sigh) so I sashed them with a fabric that sort of went , finished the quilt and donated it to our guild charity.
One year our guild had a drive where every month we donated a block to the charity pot and then someone would put them together into our standard size and someone else would quilt them. I was the only one willing to tackle the piecing. I had fun putting the sampler type quilts together since the blocks were all different sizes, several different patterns and different colors (one quilt was all the same pattern but each a different color), but it was one of the hardest things I have done.