Quote - With XSI now, for a pricetag $500 lower than 3DSMax, you get a soup to nuts major 3D system including a very strong hair module and arguably THE BEST cloth simulator in the biz

Not just syflex, it also comes with Shave, the best hair system. Well so does MAX.

Anyway you cant go wrong with MAX. XSI and MAX are pretty close in terms of features and tools. XSI wins in some areas, notably performance, flexibility and animation tools. MAX wins in terms of ease of use, modelling and more variety of plugins. Both use Syflex and Shave. MAX has better particles and XSI has better hard bodies.

MAX has an edge in renderers, though a VRay plugin for XSI is in the works also. MAX also has that plugin that hosts poser scenes, while XSI has nothing similar. XSI works better with mentalray though since it is built from the ground up to use it. Uses less RAM and renders faster. MAX also has more issues with stability then XSI, notably in heavy scenes.

Also let me throw another curve ball at you. XSI also has its low cost Foundation version ($500 or so). This version comes with almost all the tools of XSI Essential/Advanced, except that it uses XSI cloth instead of Syflex and does not have hair. XSI cloth is actually pretty good and is actually more accurate then syflex. The catch being that it is slower. And for hair you can buy a plugin for XSI called BHairy that gives you the same render results as you would with shave. But the limitation being that it requires more work to animate.

Worth checking out if you dont immediately want to spend $3k+ on anything.