This is just my opinion, of course, so mileage may vary. It really didn’t seem to be very effective in my experience. With my storm pally Sigard I tried it on a few different chars, and it didn’t seem to give very good returns when compared to most other things that you could be doing in a fight. Shaman seemed like one of the best classes to use this against, but the damage didn’t seem to deter the opponent from casting their usual compliment of maledictions. Even the outside chance of maledicting their int/wis with bat seemed to be a better option than curse of radiance. Perhaps other classes that are more traditionally suited to acolyte would find more opportunities for this power to be effective, but generally it seems as though there are almost always better options.