Recently, Consumer Reports listed tile high on the list of choice for a countertop but attibutes the grout as its weakness. The report stated that thinner joints and a darker color probably wouldn't prevent the problems with grout. I have read that epoxy grout (improvement over the older grouts that need sealing--epoxy supposedly doesn't need sealing) is difficult for the tile installer to work with and the grout can discolor. Now I have seen advertized urethane grouts (believe Bostik is one of them). It's purported to be easier to work with and doesn't discolor. I believe this manufacturer states that sealing is not necessary. Has anyone used these urethane grouts and what is your experience with them?