Pros : Weldbond is as easy to use as Elmer's and actually IS as strong as they claim. I work in schools a lot and buy this to refill smaller bottles. There are times that I have had to remove glass after a few days. In this case, many times the cement board or glass will break before the weldbond gives, even with really smooth glass. Where possible, soaking in water will loosen the bond so this glue is NOT waterproof. I now use thinset for installed or outdoor mosaics but I have outdoor vertical mosaics that have held up to freeze/thaw for over a decade and the weldbond is still holding perfectly.
Pros : This product is difficult to find in everyday hardware stores. Well worth the investment in purchasing a gallon from Delphi. It has exceptionally good adhesion.
Cons : Not having a small container to manage the flow of material you need. Must transfer to another holder or place medium on a tray to use