I wonder, what would the YB-70 and B-70 look like? How would they perform in service? Since they would be higher quality and more streamlined, they might actually go faster than the XB-70. I could also see the payload be increased, with production models being able to serve as bomb trucks like the B-1, albeit with reduced top speed while trucking bombs. They'd probably get digital cockpits at some point if they were still in service in the 90s. I could see them maybe even getting their engines switched for low bypass turbofans as an upgrade, which could increase it's reliability and top speed.
What do you think the XB-70s service would be like if it entered production? What upgrades would it recieve, how fast would the production variant go?