I really think a demo would be a good way to see if it's worth it.
Regarding boards degrading over time I'm not sure that boards that aren't ridden decay but they lose their pop with use; wood cores change their flex after repeated flexing for example.
Ultralight boards are less durable than regular boards and may not be suited for some features, but more generally construction techniques are better so boards of equal durability weigh less now than then.
Try before you buy and if you feel the difference you can decide if it's worth the expense to upgrade. 2012 stuff where available is usually pretty deeply discounted right now.