-
quite soft when dry and doesn't seem to sand as well
You obviously have more experience than me, although I have filled MANY cracks in this bastard house, I've not had a problem with it being too soft to sand. Although, that being said, I have not used Toupret interior but I've not thought easifill was lacking in that regard. I have found that the ready mix dries harder or at least more consistently than when I try to mix it. And that is absolutely because I am an idiot and winging it in terms of getting the right consistency. It just depends how much I'm doing at any one time on whether I go ready mixed or bagged for cost effectiveness reasons.
stevo_com-
It's probably only a subtle difference. I do use easifill for joints in plasterboard. It is a lot easier to feather with a sponge.
I use a mix of powder or ready mixed fillers but the ready mixed is normally for tiny quantities when you need to fix very small areas. It's worth measuring the weight of filler by a small quantity, say a plastic cup and then measuring the amount of water the manufacturer recommends to mix with that. Then you have 2 measurements you can replicate on site and your mixes will improve.
Airhead
If you use Toupret interior filler mixed with warm water it will dry in a few hours on the sort of depth you need there. You should sand what you have there now back first though.
Use Zinsser Gardz on top of the fresh filler if you don't want it 'grinning' through the new paint.
I only avoid Easifill because it's quite soft when dry and doesn't seem to sand as well.