So now we are moving from 5GB to 22GB, a much more reasonable number. Being on unlimited, I've been throttled a few times. I never hit 10GB, but sometimes go over my 5GB limit. I'm glad this is finally being fixed.
http://www.theverge.com/2015/9/16/9336783/att-unlimited-data-throttling-cap-raises-to-22gb
http://www.theverge.com/2015/9/16/9336783/att-unlimited-data-throttling-cap-raises-to-22gb