Vibrations at low RPM's (fixed u-joints and balanced driveshaft) transmission?

Dealer ship says it is the Torque Converter, and that the 2009-2014 models are the worst about this. Also the camerys have this issue just don't know what year he said. He told me to prevent this don't drive like an old man.

 

Reading this thread has me pretty concerned...I have a 2013 4x4 Tacoma 112k miles and my wife drives a 2006 4Runner 4x4 125k miles. Tranny fluid hasn't been changed since we bought them, both around 100k. What's the consensus on changing the fluid here? I was planning on changing each soon but now I'm not so sure considering the potential side effects. No issues with either vehicle currently.