Planted out two plants which seemed to establish well in 2008. Tasted the leaves last summer, and a friend and I both found them disgusting, contrary to highly positive reports from permaculture literature. Over the winter, both plants died to the ground, which surprised me. One plant re-sprouted this year and looks healthy, while the other plant never re-sprouted. I expected them to be hardier in our climate. On a positive note, the plant which re-sprouted now makes leaves which taste very good, with the salt-flavor-burst and a pleasant aftertaste.
And an update written from memory June 2012: later in the season the leaves started tasting disgusting again. The following winter killed the remaining plant off for good.
I remember very little about the A. halimus, except that it suffered from the same die-back or die-off problems over the winter(s). If I ever tasted it, it didn't taste good enough for me to have marked it in my memory as worth eating.
Both species should easily handle the coldness of our winters (with A. halimus approaching marginal hardiness at about 10F, but still below our usual coldest temps). However, the Plants for a Future database reports that both plants "are apt to succumb to winter wet when grown on heavy or rich soil" which probably explains our winter failures.
I see a lot of potential for these species, but we would need to figure out how to give them good drainage over the winter, and experiment more to have consistently good tasting leaves. Were I to try them again, I would experiment with soil conditions (try some poor soil instead of just rich garden soil), obtain seeds or preferably cuttings from shrubs known to have tasty leaves, and pay more attention to seasonal effects on the flavor.