Unity / Blender animations

Hello everybody! I'm new to Unity and Blender, and I have a lot to learn. I try to learn a new thing every day, and the last few days I've been tinkering with the workflow between Unity and Blender. I've rigged up a simple character and got it working well enough to learn more about animation.

Correct me if I am wrong, but I'm under the impression I have a choice between animating in Blender or in Unity, since the whole Armature shows up nicely after import. But I have no idea why I should choose one over the other at this point. I think I lean towards doing it in Unity since that seems easier to tweak, but there are probably caveats to both methods. Can anyone give me some tips and pointers about this?

I may be biased towards thinking this since my background is in programming rather then character animation. While my first project will have simple animations, I'd be interested in allowing them to blend into each other a bit. I'm under the impression this can only be done when you animate in Unity, but I would be glad to be wrong.