While I love the flavor of the crystalline creature form of a superior psicrystal, the text in the book (Psicrystals expanded) is rather brief on the subject and there's a few things I was wondering about.
* As the psion levels up, they can choose animals from an expanded list, mfor example bigger ones. Does being able choose from large sized animal companions allow you to choose a "grown" creature that normally starts smaller or does it just refer to the base form?
For example, a psionic character at lv 7 can pick "any large animal from the animal companion list" but the amount of animal companions that starts out large... well, there's 2 of them. Whereas many other creatures grow to large at varying levels.
* How closely do they resemble animal companions in function? Is it just the stats or do they get the usual animal companion bonuses and stuff?
There's probably a bunch of other odd things I haven't thought of either, as the entry crams a potentially rather big change into a very short description. But maybe someone has experience with this and can explain a bit?