What just happened? Android or iOS? It's an argument that's been raging for years. Former Microsoft boss Bill Gates knows which one he prefers: unsurprisingly, it's Android, though he does use an iPhone when required.

Speaking to CNBC and NY Times journalist Andrew Ross Sorkin on the invite-only Clubhouse app (via Android Central), Gates confirmed that his long preference for the Android mobile operating system hasn't changed---but he doesn't avoid Apple handsets altogether.

Gates said he opts for Google's ecosystem because "Some of the Android manufacturers pre-install Microsoft software in a way that makes it easy for me and they're more flexible about how the software connects up with the operating system so that's what I've ended up getting used to."

While Gates has a day-to-day Android device, he uses an iPhone to keep up-to-date with everything and for other activities, such as using the iPhone-only Clubhouse app.

Back in 2019, Gates said his greatest mistake was losing out to Google in the mobile landscape. "That was a natural thing for Microsoft to win. It really is winner take all," he said. "There's room for exactly one non-Apple operating system and what's that worth? $400 billion that would be transferred from company G [Google] to company M [Microsoft]."

Gates was also asked about which companies he believes are doing the most exciting work. Google and Microsoft were his choices, though he added that "Amazon's doing great work, Apple's doing great work, Facebook."

"But, in terms of really pushing the boundaries of computer science and architecture and AI, I'd say Google and Microsoft have a strong R&D commitment --- both stuff they share openly and things they focus on for their own products."

Elsewhere, Gates cast some skepticism over the Apple car. "I doubt they'll make the same margin they make on the iPhone," he said, adding that, unlike electric vehicles, a future filled with autonomous cars isn't a certainty.