On top of that: The implementation of the grind-tree is more than lazy, so if you unlock the second slot, so you need to upgrind a lower tiered ship to get the next slot and still gain XP on that bigger ship, your gained XP is lost. So if you do not keep exactly track where you are right now in the grind-tree you loose a lot of time and XP.
If i would only need to grind my beloved conni, i wouldn't complain that much, but that i need to grind for it the by me hated endymion, and also the even more by me behated trincomalee and also the surprise and for that the renomee, and for that the mercury and for that the privateer and for that the basic cutter... this is just out of my mind how somebody could think that this an expierience you want to give somebody.