Aloe greatheadii. Difficulty? Effortless. Thirsty? No. Maintenance? Almost none. Climate appropriate? Very. Pests? None. Diseases? None.
Do I love this plant? Of course not! I'm pulling it out.
To be replaced with the Echeverias that are engulfed by a Grevillea, and with the Agave 'Ivory Curls' engulfed by Leucospermum 'Yellow Bird':
I'm pulling A. greatheadii out from here, too:
The patch on the left to be replaced with the repeat blooming Aloe 'Cynthia Gitty'; the patch on the right with the repeat blooming Aloe 'Roikoppe'. For no better reason than because I think they are prettier and will make the garden look better. Although they do bloom a lot more (A. greatheadii blooms only once a year), and thereby feed hummingbirds and bees a lot more, and need no more water or maintenance than does A. greatheadii. I still feel bad about pulling all those happy healthy plants. I hate it when this happens, but I'm doing it anyway. Without finding it at all a comfortable role, I'm playing God.