This is probably an odd take on the new relic and AF1+1, but...
The AF2 hat was the one that stuck out to me the most due to Grimoire cast reduction similar to the AF1 shoes. If the bonus is the same (-2% casting time, -5% recast time), this will allow SCH/RDM to break the final Cure III-IV casting time tier at 35%.
Previously, the best a SCH/RDM could do was 34% (or 34.5%).
(Kuuhalee's testing thread if you don't know about cure casting time tiers)
Cure Cast Time - Detailed Testing (Updated-05/13/08) - Killing Ifrit
0%-16% Fast Cast combinations = ~2.53 seconds cast
17-34% Fast Cast combinations = ~2.01 seconds cast
35% + Fast Cast Combinations = ~1.65 seconds cast
/RDM sub Fast Cast = 20%
Light Arts Casting = 10%
Loquacious Earring = 2%
AF1 Shoes = 2% (or 2.5% can't tell)
AF2 Head = 2% (assuming same as AF1 Shoes)
This will put you at 36%. I suppose someone will have to test to see if the bonus is 2 or 2.5%. If it's 2.5% then you won't need the earring to hit the final tier.
This gives you an extra .4 second boost on your cure time, which is rather strong if you're spamming or need a cure quickly.
This update puts SCH on par with WHM on pure curing speed.
EDIT:
Just in case anyone is wondering, Wiki is wrong about AF1 shoes and claims it's -9% casting time. This is INCORRECT. It's 2% or 2.5%. The effect works the opposite of fast cast. Fast cast has twice the reduction in casting time relative to recast time. Grimoire bonus is twice the reduction in recast time relative to casting time.
XI Wiki



