When casting remote attack spells...

[licker]

... what helps more, higher magic levels, or more penetration?

Mostly this is for the spells which target MR I suppose, but does penetration generally help even with things like Fires from afar?

Which is more beneficial to raise, penetration or levels?

Take Vengance of the dead for example, it is S3D1, are you better off going S4, or using a penetration item? Boosting death has no effect anyway right? Its always the 'primary' magic skill which matters?