Hi, I am currently considering XSI (have not used 3D since Alias PA a few years back). I am less in need of sophisticated character animation and modelling than I am in organic "design" tools;
sophisticated and integrated dynamics (hard and soft, "hypermatter", liquids, cloth/fur) and particles
sophisticated lighting control (volumetric, caustics if possible, glows, etc.)
Is XSI "overkill" in it's "character animation" for my needs, would Maya or even (gasp) 3D-Studio meet my needs better?