Muscle constraints messing up animation

Been scratching my head over this one for a while now :|

Long version: I'm trying to import an animation into Mecanim to be as accurate as possible to the .fbx file but the muscle system in the Humanoid rig keeps getting in the way for me. The constraints influence the pose in such a way it just ends up looking awkward and stiff and more importantly offsetting hands and limbs from positions that I need them to be at.

I've tried playing around with the Muscle settings but no luck. There are so many sliders and it takes ages to hop back and fourth between game-view and muscle setup just to see if I am getting closer or not(the preview does not work for poses as far as I know?). Then the dread of having to redo this process every time I make a new animation or change an existing one... I also did try give each limb a constraint limit of -180 to 180 in hopes that would mean free rotation until the animation itself would tell the bone to stop but I discovered it just made bones rotate to an extreme instead...

I really just want the animation to play exactly like how I saved it. It looks great with Animation Type: Legacy for instance. So that would normally be my solution, just go with Legacy, however we still we need Mecanim for all the other nice things it can do so well.

So Legacy mode is not an option this time I'm afraid.

Short version: How do I make my animation look just the way I exported it(without having to spend hours tweaking muscle sliders back and forth)?

[edit: It appears the problem was solved by updating to latest Unity. 4.3.2f1]