Ah, thanks for clearing that up guys.
Either way, it's still a really nice ability. Anybody know of a good, uncapped, spell/ability that scales by caster level?
Also, since nobody seems to be mentioning it:
Greyflame weapons are awesome for a character with UMD. A +1 ability that gives you +1 to hit, +1d6 untyped damage, and bypasses two types of DR at once? Yes please. Requires a swift action and a DC 21 UMD check (one higher than a wand) to activate for a round, but you can choose between two different modes to bypass either DR/Good and /Silver or DR/Evil and /Cold Iron. Slap this on an adamantine weapon and you're good.
The only drawback is that your GM might not let you UMD this, because of the way it's worded. Normally you have to use the channel energy class feature to channel either positive or negative energy into the weapon to activate it (hence the two modes), and UMD explicitly states that it lets you
emulate class features for the purpose of activating a device but not actually use them. It basically comes down to whether your GM sides with the "I'm not actually channeling energy, I'm just using UMD to fake it in order to activate a magic item" argument or not.
Personally I think that line exists more to prevent rogues from "stealing" everyone else's class features and running around using them all day, but I really like greyflame weapons so that might be coloring my interpretation.