In hardcore, the only use you give to personal stash is:
You go magic find for a while. One of two things happen:
A) items worth getting are dropped. You pick them and move them to personal stash, until personal stash is full.
B) Big value item dropped. The one you can trade for a lot or the one you instantly want to your other character and cant afford to lose.
Anytime A or B happen, you mule your items. That’s it. In practice you dont even need personal space for that, having shared stash. In softcore is the same, but only applies A, not A and B. basically is the same problem.
The new situation is now, in fact, now you will fill your 3 shared tabs. When you do that, then you will mule ALL three tabs to other mules (for example, the sigon mule, the runes mule, the trade mule, the helmets mule, the perfect gems mule, etc).
Then, you go magic find again and refil those 3 tabs.
People think those 3 tabs will be full and its the place for changin items from character to character but this wont ever happen. People are wrong, those threee tabs wont have our items. What will happen is those 3 tabs are temporary muling space, like a fast way to put everything into. More or less the same as the floor before. You before put things on the florr and then mule in and out.
Now you will do that, but without losing items. But we still need like a lot of character slots for this system to work.
But the mechanics will be sadly the same as before. Our real items wont be in those 3 tabs, will be in mules. We dont want that.
Which would be desired, as advertised for us, is not 3, but 30++ shared tabs (even paid). We would love not havin to mule in and out characters. But we will be forced to do it anyway, just like before, according to the way development is going.
path of Exile is perfect in the shared stash thing. They dont even have a personal one, is not needed at all. Take a look at that game, devs, learn something frmo it please. Muling is sooo easy and convenient there.