First, he shoots himself in the ethics foot in one area. Call it either the demarcation problem, per old philosophy friend Massimo Pigliucci, or else call it the sorites paradox.
Among things he says many people get wrong, ethically (and he seems to be talking about his fellow professionals in the field, not just outsiders) is something like blood doping for bicyclists. He says he is OK with low-level doping.
That leads to two immediate questions:
1. What is "low level" vs "high level" doping? That's more a demarcation problem than sorites issue, but could be a bit of both. In fact, I see them as interrelated. How many micro-moles of extra oxygen, if I'm oxygen-loading, to reverse the sorites paradox, can I add before I move from low-level to high-level?
2. Why NOT on high-level doping? (He never says why not, in the interview.)
His talk about eugenics is overall more ethically reasonable. That includes the part that classism issues will arise with it until we move to a post-capitalist world. (I agree, and use the word post-capitalist rather than anti-capitalist, in part because of any Marxist implications it has.)
His part about lifespan extension, though, is a fail, especially since he talked about moving to a post-capitalist world on eugenics. Our planet is getting closer and closer to a "carrying capacity" problem. When we hit 9 billion in another 30 years or whatever, and 1 billion more than today of that number trying to have a halfway "Western" lifestyle, including air conditioning that exacerbates climate change in a negative feedback loop, we'll be in trouble. Working to extend the average human lifespan to 120 or more will just put all those problems on steroids, and Savulescu misses that entirely. He does mention resource depletion later, as a separate ethical issue, but doesn't make a direct connection.
Regular readers of my philosophy-related writing know I'm not a system-builder. But, I do think you have to have a systemic consideration, and not just an ad hoc consideration, of empirical facts on, or likely to be on, the table.
Savulescu fails to do that. And, it's not necessarily him alone. Utilitarianism in general at least runs that risk.