Spell Mastery, powerful, but too powerful?

[malcolm_n]

Okay, homebrew feat I was thinking of for Epic tier Wizards.

Spell Mastery
Tier: Epic
Benefit: Pick two wizard spells that share a usage keyword and level from your spellbook. You now decide which spell to cast when you cast it. After you cast that spell, you cannot cast it, or the other, until you would otherwise regain that spell.
Special: You can take this feat multiple times. Each time you take this feat, pick two new spells that share a level in which to apply the benefit.

So, with expanded spellbook, you still can't pick all 3 of your 29th level dailies and cast whichever whenever, but you can pick 2 of them and mix/match. Coupled with the powers out there which let you recharge dailies, it could be decently powerful.