Unity: character deforms differently than he does in Blender

I’ve exported a character from Blender to Unity 4
The character deforms odd in Unity, but everything looks perfect in blender.

What I mean is, that it looks like there is no gradation (0, 0.25, 0.5, 0.75, 1.0) between the vertex groups in Unity, like it just clamps all the groups to be either 1 or zero (at least that how it looks)

Is this a limitation in Unity or am I doing something wrong?

I have had no problems using my armature animations in Unity. Native .blend files work good but the Devs recommend FBX for your final game build. Make sure to use the Legacy rig option if you don’t stick to the Mecanim guidelines.

Unity has a limit of up to 4 bones effecting a vertex, and that can be an issue on complex rigs that effect an area smoothly between more than 4 bones.
Also, you have not shown anything for us to diagnose, so we can’t really say exactly what is happening.

You should also triangulate your mesh before export. It may deform differently if the triangles are running in different directions.