I use it all the time. After I spray baste, I use the water soluble thread and baste a couple of rows in each direction to help hold it together. I don't have a dedicated sewing area, so my quilts get a lot of handling between the time I spray baste and when I finish the quilt. I've made quite a few quilts and am still on my 2nd spool. It goes a long way.
I don't do trapunto, so I can't comment on using it for that application.