Not content with taking apart the controller, Blu-Ray player and pricing, Microsoft is now targeting its verbal attacks on Sony's online strategy as the US firm races to cement its market advantage ahead of PS3's launch.
Sony used its pre-E3 media briefing to provide the most detailed demonstration yet of its next-gen system's planned online functionality. But Microsoft, which is now in the second generation of its successful Live service, has dismissed PS3 simply as playing catch up in this area by including features already established on Xbox.
"I'm flattered that they've followed our clear direction," Lewis told Eurogamer TV, in the second part of an exclusive interview broadcast today. "Plagiarism's a good thing - that in itself isn't such a problem, it's what the market wants. But we've known that's what the market wanted all along."
"It's good to see them catching up in that regard," he noted. "I think the service is still hazy in my view in terms of how it's really going to work for the consumer - how the pricing's going to work still to me seems very unclear."
Microsoft used its press conference to talk up the ongoing achievements of Xbox Live, with Bill Gates announcing the next evolutionary step for the service, the cross-platform Live Anywhere initiative. Online is certainly what the US firm believes is its biggest asset in the next-gen battle, and Lewis picked upon the language used by his rival to press home what he believes is a significant advantage.
"[Sony] talk about the online component - the analogy used was the air conditioning unit in a car. From our point of view, right from version one, online gaming was built right into the heart of the first Xbox. For us it was the engine; it wasn't some peripheral component people may or may not want to use. It was right at the heart of the proposition then and now.
"I think we can be very confident that our service continues to develop. It's a fully connected, seamless environment - we're in a fantastic position there already."
Elsewhere in the interview, UK boss Neil Thompson discusses the importance of Viva Pinata to 360 as a "catalyst" to broaden the portfolio of 360, and argues that content will prove the decisive factor at retail this Christmas.