I love the idea of the magus, and when I saw the skirnir archetype, it made me really excited. I made a skirnir, and played him to level 3, and it was not quite as good as I expected. I read a bit more in-depth after that, and the tradeoffs you get for the innate shield abilities and feats makes it almost not worth playing the skirnir. But I still really like the thought of a shield-bashing magus.
It seems as though the thought behind the skirnir is that you fight with a weapon and a shield AND get the magus powers, and that's why the tradeoffs are so severe (one less spell per level, spell combat at level 8). But what if you just want to use the shield as your weapon and have an empty off-hand? That's how I played my skirnir, and I think if you're playing that way, you shouldn't get nerfed the way the skirnir does.
So my question is: would it be better to roll a straight magus and sink the feats into shield proficiencies, or roll a skirnir and bear with the reduced spell count and no spell combat until level 8?
Edited for clarity.