1. Full Packages ompare to Unity\Unreal packages

There are two  kinds of assets in my store. All animated characters comes in both variants.
Full Package contains original files (3D Studio MAX and BIP Character Studio animation clips in case it is an animated character) They usually contains also FBX, OBJ, DAE (Collada) files, and texture files of course. Such package gives to customer ability use original files in order to change, to improve and to add things to the model, scene or character. Especially it is useful with animated characters. When customer buys Full Package he automatically get ability to download Unity Package as well.
Unity package contains only FBX and texture files contaned  in Unity Asset file with basic shader and basic animation setup. Unity Package usually cost less then Full package

2. Animation collections and single animations.

These assets is directed to 3D artists which familiar with 3D Studio MAX package generally and with 3D MAX Character Studio animation module in particular. Most of these animations are ideal cycles and all of it prepped to be used for video game charters or for crowd simulation in move scenes. There are also animated FBX files in every package.
Generally animations will work with every humanoid charcter which rigged and skinned with help of 3D MAX Character Studio. But of course some correction may be necessary due to difference between bones size and bone number.

3. Animations which can be used with Unity 5.X, 4.X and 3.X

All single animations and animation collections which not under unity assets sub-menu DONT FIT UNITY MECHANIM. I cannot guarantee that they will work well with Unity 3 as well. These assets designed for 3D Studio MAX Character Studio user. And can be used in Maya or Blender with some restrictions. 
Only animation collections and single animations found under unity assets sub-menuwork with Unity 5,  4 and 3 correctly.