Hi Doug
Like Harry said, we'd need more info on your shower project to give you advice about Redgard. It's a good product, but it won't do miracles.
Now, the Peel and Stick Easymat is just terrible stuff. My one and only experience with it was not good. It's almost impossible to get the stuff to unroll and lay flat. In fact, I had to staple it down to keep it from curling. There is a non peel and stick version, that other guys have had good luck with, but I don't think it's available in Canada yet.
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Brian