Encephalartos gratus' range is one of the inevitable contradictions arising out of the global interest in collecting cycads. Its habitat in the wild is deciduous forest and it survives stony terrain in South-eastern Malawi, and north-eastern Mozambique. In the rest of the world though it is one of the most common and widespread Encephalartos. It grows fast, when it cones it produces a lot of seed and its seed germinates well, hence it has spread better than most of its kin through nurseries and botanic gardens.
It will do very well in sun and won't mind shade either but it loves a bit of humidity which is why this one is doing so well here in the Caribbean. It'll eventually form a trunk to 2.5m, suckering being fairly uncommon.
Its also not too spikey so by Encephalartos standards its about as close to a normal plant as they come. If your local nursery or BG has an unnamed Encephalartos this is one of the first things I'd try to key it out too (it should be noted for example that the plant above is itself unlabeled).