I always thought it was just me, but when I first entered Naxx with my nerfed Volley, it still seemed pretty overpowered, I still managed to top the trash meters with ease. However, once I and others around me geared up, it seemed harder for me to top meters for 5 mans and AOE-able trash. I figured it scaled with gear but I never heard any complaints to tell me otherwise.

Well, here’s a small comment by Ghostcrawler:
“The AP coefficient of Volley has been increased from 0.0586 to 0.0837. Base points did not change. This probably did not make the patch notes.”