Biped vs. Cat - What to use?Over and over the question of Biped comes up or a studio uses Biped and doesn't have a good idea about why they shouldn't be using it.
But what is the alternative?
Cat would be better than Biped at least in the newer version of Max *2013+. Biped, while tolerable only for animation in pinch* (I only say this because some animators only have ever used it), but if you have any need for motion capture don't use it. If the motion capture will be delivered to you from an outside vendor or you want the time spent on capture to not be a waste of money, then under no circumstances use biped.
How is it a waste of money you might be thinking? First Biped and Biped rigs are limited in the way the rig moves, has bones in less than ideal places for re targeting human motion on to, has issues with getting motion capture data on to it while keeping the shoulders and elbows the same as the source data, it goes on. So you spend lots of money to capture the moves, pay for clean up and high detail data and then it gets trashed loading on to Biped. It is like taking a really nice high resolution picture and then compress and shrink it down to a blurry mess then trying to print it and expect it to look good.
Cat is a more flexible system, has improved compatibility with MotionBuilder and is a more modern rigging system that won't trash your data.