MacworldApple is expected to launch an extra-thin model when it unveils the iPhone 17 line-up next year. But exactly how thin are we talking? A new report appears to confirm the figure is 6mm, which would make the iPhone 17 Air/Slim the thinnest smartphone Apple has ever released.The analyst Jeff Pu put out a research note Monday supporting a recent rumor about the devices thickness. We agreed with the recent chatter of [a] 6mm thickness ultra-slim design of the iPhone 17 Slim model, he wrote in the note, seen by MacRumors.At 6mm, the Air would easily snatch the record previously held by the 6.9mm iPhone 6; the iPhone 16 is a comparatively chunky 7.8mm thick, while the 16 Pro and 16 Pro Max are a positively obese 8.25mm. Oddly enough, as MacRumors points out, you can get a thinner iPad: the 13- and 11-inch versions of the latest iPad Pro are just 5.1mm and 5.3mm respectively. And the final iPod nano came in under 6mm too, not that this is a fair comparison against a full smartphone.As ever with rumored Apple products, the iPhone 17 Air has come in for plenty of criticism long before its even been announced. Theres a sense among pundits that 6mm wouldnt be thin enough to warrant an Air or Slim branding or the likely high price tag; MacRumors itself wrote a story earlier this month complaining that the device may not be much thinner than the iPhone 6, as if being thinner than the thinnest ever iPhone, which incidentally had just a 4.7-inch screen and vastly inferior components and cameras, would not be an engineering feat worth celebrating.Conversely, most of the negative discussion on Reddit argues that slimming down to 6mm goes beyond usefulness. In this thread:Hard no for me. Gimme thicker with big battery.Does it really matter when most people will slap a massive case and screen protector on there? Give me a thicker phone with better battery life.I dont think thinness or lightness is a huge priority.Why the obsession to go thin?I never loved the thinness of my iPhone 6s. It was just too thin. [Editors note: the iPhone 6s was slightly thicker than the iPhone 6, at 7.1mm.]Were still a long way off the launch of the iPhone 17 series, and Apple may find ways between now and then to further slim down the Air modelperhaps even rivaling the iPad Pro. But with half of the community complaining that its too thick and the other half complaining that its too thin, it feels like Apple might have got the balance about right.Catch all the latest news and rumors in our regularly updated iPhone 17 superguide. Or, if you dont want to wait until next fall, pick up a bargain on the current range with our roundup of the best Black Friday iPhone deals.