I know this thread is a bit old. But I made the switch to XSI, and boy do one get lost in there!!
Setting up materials with all the node stuff is much more complex then "layerstyle" texturing in Carrara. Not so intuitive when power is not needed.
That goes for all things in XSI compared to Carrara. But you can do almost whatever you want, animationwise. Foundation has no hair though.
There are costumizable rigs in XSI but this one is better:
http://3dquakers1.com/webroot5/review.php?id=10
Modeling is great in XSI. But it is adifferent style then I was used to in Hex. Move around vertices/boxmodeling style.
I think that the problem with complex software as XSI you get sucked in
thinking that you have to grasp everything there is. But one cant at first.
So it gets overwhelming. Like Reactor says, I to wouldent like to set up a
landscape and render it in XSI.
There still some quirks with Z-brush displacements. Mentalray issues..
Great thing with XSI is that it is very costumable. You can organize layout like you want. Make buttons that do this and that with simple drag and drop expressions.
I was heading for C4D but thought it was overpriced, and CA is better in
XSI anyway. Even if you have to buy the foundationversion at every upgradelevel(you dont have to) it still is a good bargin.
I qoute Reactor:
If you like things simple, stick with Carrara