It is a peace for him that won't last; he absolutely has his Father's tendency to just Not Be Content. But for now it's more than enough. He ducks his head with the implied compliment. "You also deserve credit for that--my version of you built the time machine and never gave up, after all."

As for the subject of Vegeta...

"I admit, it's been a bit hard to experience myself. I'm glad for it, don't get me wrong, but it's just... Such a change from when I first showed up." A pause, and he shifts his gaze to her, slightly sideways. "I'm sure you also wore him down over time, Mom." He's teasing her a bit.