rebuilding a downstair bathroom, on concrete slab. i had pulled out the 36x36 70's fiberglass shower earlier. galvanized plumbing was leaking. i'd really like to tile the shower instead of a replacement fiberglass unit, and ran across this: http://www.schluter.com/8_4_kerdi_shower_kit_6551.aspx a friend of mine said he wouldn't install that particular system, he thought embedding the waterproof goretex like layer in mud was asking for trouble. does anybody have any particular recommendation of a good shower pan to tile over? i don't want leaks, i don't want to pull it apart in 5 years, i want "one and done".