I have been using the spray baste stuff for up to queen size quilts and love it.
I have been using the Elmers dot style for smaller quilts and it seems to work very well also. In fact, I use it around the edges of the large quilts where I miss with the spray. Dot on and then press.
On another string, someone had mentioned using Elmer for piecing and matching blocks instead of pinning so I tried it and love it. Especially after they said the glue baste product is made by Elmer.
I have not tried the glue/water spray mix but wouild love to know the ratio as well. I think the only thing that would be different from spray baste is the dry time before ironing, but then maybe not if I don't get too heavy handed with the spray.