In June of 2008 we built a set of cabinets for a patio kitchen for a client. That was the first time I used Sipo Dominoes, 5mm.
Those Sipo Dominoes have stood up very well. The client and their designer were so pleased with the job they have referred many other outdoor cabinet projects to us. Perhaps there were other ways I could have joined the parts. Prior to the arrival of the Domino in the USA I avoid building outdoor cabinets.
Perhaps the Beech Dominoes would have worked. I never experimented with them outdoors. True, 5mm Sipo Dominoes are slightly more than twice the unit price of Beech. Fortunately a lot of Dominoes fit in a small space, so I stock a lot of both kinds. Perhaps I am over-doing storage, but as soon as I open a factory container, I put those Dominoes into ziplock plastic bags to keep them fresh.