Well, I have an interim report. We got my buddy's EIII 3-12x sighted in and programmed. I'm impressed so far. It has 1/8 MOA adjustments. Ranging is quick and accurate, and calculated bullet drop jibes with the ballistics of his load. Haven't used it at night with a light yet, but it works fine at dusk/dark in low ambient light conditions. The glass is better than expected, comparable to my Burris Fullfield LRS2 4.5-16x's. I see no reason why it wouldn't work at night with a light. The only downside I can see is that it is one massive scope and probably pretty heavy, though not noticably so on his R25.
Hopefully we'll take it out hunting this weekend. I suspect those 600 yard "sitters" are now in a lot of trouble. I'll keep you posted.