What does Arcane Training really get a Half-Elf?

[I'm Hiding In Your Closet]

It's one of the precious few alternatives to the Multitalented racial feature, and one of still fewer of those that is legal in Pathfinder Society - but I have a bit of trouble understanding what good it does, both for those who take it to pursue an arcane spellcasting class, as well as those who take levels in some completely different class and only get the ability to wield spell-trigger/completion items for that class as a 1st-level caster.

Anyone have a firm grasp of this they can share?

[Aldizog]

It basically lets you use wands without UMD. Wands of Shield and True Strike are not bad for fighters (self-only can't be potions). You are giving up 1 HP/level (so Toughness) for auto-succeed UMD on wizard (or bard, witch, whatever you pick) wands and staves. Not quite as good for scrolls as they have ASF.

[WRoy]

It's still pretty good for low-level utility scrolls that you may want to use outside of combat (as long as you have the time to avoid ASF), letting you cut in half the cost of 1st-lvl arcane spells you otherwise would have purchased as potions. Scrolls of 2nd-lvl arcane utility spells are also viable, with only a 10% chance of activation failure and 2% overall chance of mishap (assuming Wis 10).

[David knott 242]

For a member of an arcane spellcasting class, you can use scrolls with spells above your level to cast at a lower chance of failure and you can use a staff at a higher effective level. It is a relatively minor benefit, but it is a heck of a lot better than the nothing you would get if you kept the Multitalented racial feature and never multiclassed.