Had a 15lb V2 sanded OOB finish with the 315 drill, it was a great ball on med oil/fresh backends, heavy oil (doesn't exist) and transitional carry down. I personally liked the drilling, but found it too difficult to find a 1" pin out with less than 3oz top. The best thing about the drilling was if you over hit it or grabbed it too much, the drilling didn't make it over react, allowing you to stay away from the splits, and if you missed it the surface made it grab.
I now throw 14lb after elbow surgery, but never went back to 15 because of the versatility of 14lbs. But with other drillings, like RICO, I have found it easier to get a similar reaction and not have to keep searching for specific pin distances. Now I never drilled a 315* in a 14lb ball to make a true comparison, but due to RICO, I really don't see the need.
I think the benefit of a 315 drill is negated if you use a RICO drill and select the right type of ball for the reaction you are looking for. My personal favorite is to drill a high MB ball RICO expecting a little more back end versus a symmetrical ball. Symmetrical ball RICO will roll more evenly. Asymmetrical is more agressive in the back. Taking both reactions into account, IMHO you can cover the lane condition that a 315 drill would work best on with a RICO drill.
Hope that helps.
