Yesterday on the Culp-Bossier, I was was at the end of a 70 meter pitch, wandering around blank face and detached flakes looking for a belay anchor. Verbal communication was impossible (wind, distance, rock). Rope communication would likely have been very suspect (rope drag, nearly 70m of rope out). With a radio, I was easily able to ask how much rope was left, and stretch it to the max to reach the only decent gear around without danger of running short or miscommunication.
I would have managed without, but the radio sped up the process and reduced stress for both of us. I was glad to have them.