Myrrh, Frankincense, and Steel: Kurald Galain's Guide to the Magus

[upho]

Thank you. Seize the Opportunity is not so great because you can already use trip and disarm as an attack of opportunity.

For magi in general, I guess StO can be interesting primarily because it makes focusing on dirty trick much more worthwhile, giving a potentially highly effective debuff/control tool without opponent size caps and which remains largely unaffected by immunities even in higher levels. Both trip and disarm are, or at least become in later levels, significantly more limited in most games IME.

Especially for a Str-size-reach AoO build, it can also really ramp up damage via Vital Strike (for example combined with trip generated AoOs). Or control/mobility shenanigans with bull rush and/or overrun (and for example a 2-level dip into siegebreaker fighter for extra fun).

Finally, if someone ever makes a grapple focused magus build viable, StO allows you to both initiate and then immediately maintain a grapple (with some supporting options), tying up a foe using only two AoOs. Hilarious and potentially devastatingly effective, although admittedly probably not particularly fitting for magus based builds.

Elemental Focus feat doesn't seem to work on spell damage or magic weapon damage, meaning that it remains a good choice to pick a different element. I haven't gotten around to adding specific disciplines yet.

Yeah, it's not very interesting before 10th level, although it can have some limited benefits earlier if focusing on Elemental Flux.

Dragon's Breath is a decent choice.

Yep. I realize my suggestion of Pyrotechnic Eruption was highly colored by the specific context of a bladecaster.