Ummm... actually Magic of Mystery protects more than the Subtle magic.
Why? Because Subtle Magic says 'caster of the divination' which means spells only (SLA are activated, not cast).
whereas Magic of Mystery protects against spells, SLAs, and magic items.
as for the non-halfling thing? that's an adaptation, which is a variant of the standard requirements of the class, which requires additional dm approval (besides allowing both classes).
on top of that, the Wizard has easier prereqs, many of the feats can be gained for free. The Tower of High Sorcery gets rid of the wizard specialization requirement.
upside, full casting vs 7/10
downside, arcane only.