There might be more users on the Verizon Wireless 4G LTE network then AT&T's network and actively using it.
I'm most definitely NOT a VZW employee. If a post answered your question, please mark it as the answer.
I am in San Diego and have both AT&T and Verizon 4G LTE devices. I do not notice any significant difference. Some places AT&T faster, others Verizon. Both are more than fast enough that data speeds are no longer limiting me. Often they approach and sometimes exceed my home internet speed of 30/5