It will inevitably decline. Depends on your concept of long term, and your concept of container size, of course.
I pushed back the ticking clock 1 year with this repot. I can hear it in the background already. The other ones in 3 gallon pots are going away because they will start to get cranky (been there, seen that). And really winter is the time to put these in the ground. These plants fully approve of winter rainfall, and it's a much deeper and richer experience in the landscape. A newly installed plant only really begins to become established once it has experienced mother nature's sweet wet kiss.
The plant in the picture is 3 years old. It is not the biggest of its litter, mainly because it branched late and less in comparison.
I would say you have about 5 years from seed with Aloidendron, given decent care, before you start to cross the line into pots that are unsafe for spinally challenged folk to move around. I have seen truly gigantic ramos in container boxes, but I don't think that's within reach for ordinary gardeners, especially outside their native climate (in the case of that plant perhaps more so than dichotoma, winter rainfall is about as important as summer drought).
