As discussed in the balance conspiracy chat, here's what I think:
This is an overall very welcome change, because the disparity between small and large cloaks is currently too great.
Particularly for small cloaks, basing them on ammo will allow snubcraft other than the heaviest bombers to use cloaks effectively.
With large cloaks, it's less simple. Currently, the maximum time larger transports can cloak is excessive, but the basic system of sacrificing a dynamic amount of cargo space for cloaking time makes sense. While the large cargo requirement of the cloak would mean there may not be a huge absolute advantage in free cargo space, it is the dynamism of the system I would miss.
With a non-flexible requirement of cargo space, any transport with a cloak will always have the maximum cloaking duration available. The current system requires planning: How long will I realistically need to cloak during this trip? How much fuel can I really afford to take on? A hard cloaking time limit would take that step away.
Anyway. Other than that, the new system and times will be much better, especially for snubs.