UMD is awesome at high levels. A player can in/effectively become a partial/full spellcaster. Scrolls are expensive and they are not as likely to penetrate SR, but at high lvls money is irrelevant and one can use scrolls for buffs.

Rgs can take full advantage of the clericzilla melee buffs. With a DC29 UMD on a Divine Power a rg can get a fighter's BAB. Foresight guarantee's your rg will always act in a surprise rnd. Spell Turning anyone? The clr need not survive every fight when your rg can use a scroll of raise dead or true res. These are just PHB spells so far.