One reason Verizon is moving early on 5G is they need to have people think they are by far the best. Their entire business model is based on people paying more because they believe Verizon is superior. That's no longer true; AT&T and T-Mobile are so close to Verizon in quality most people wouldn't notice the difference. Jennie has T-Mobile here in New York, a hard city to service. She's not seeing any problems.
The chart at the left from Open Signal shows T-Mobile running faster in several parts of the country. They've hired Kevin Fitchard to blog for them. He's doing excellent work, as he did at GigaOm. Verizon of course has data from another source saying they are better.
My guess is that Verizon is slightly better, especially in the most rural 5% of the country.