The company describes the wearable device as “a revolutionary spatial computer that seamlessly blends digital content with the physical world,” with the Vision Pro promising to deliver “extraordinary new experiences,” “an infinite canvas for apps at work and at home,” and “immersive environments.”

“In the same way that Mac introduced us to personal computing,” Apple CEO Tim Cook said as he launched the headset on Monday, “Vision Pro will introduce us to spatial computing.”

Despite Cook’s assertions that the headset will be a game changer, the product was met with a mixed reception, with many impressed by its capabilities but flabbergasted by the hefty price tag.

One of the people who did not appear to be fully won over by the headset was Tony Fadell—the inventor of the iPod who worked closely with Steve Jobs and, for almost a decade, led the team at Apple that developed the iPod and the first three generations of the iPhone.

While Fadell—who is known as the “father of the iPod”—labeled the Vision Pro “a technological tour de force” and “very impressive,” he expressed skepticism over the headset’s potential.

“With the ‘consumer’ apps and marketing for $3,500 [with] two-hour battery life, Apple has truly ‘jumped the shark,’” he said in a tweet on Tuesday.

The phrase “jump the shark” refers to a creative project or company that has exhausted its core ideas and has reached a point where it starts to decline in quality, artistic value, or popularity.

A spokesperson for Apple did not respond to Fortune’s request for comment.

Mixed reviews

Fadell, who has sold startups to both Apple and Google, was an early pioneer of mobile devices, and was recruited by Steve Jobs to build the iPod in 2001. After leaving Apple in 2008, he founded Nest Labs, which makes the Nest thermostat.

Fadell argued in a subsequent tweet on Tuesday that even if Apple improves the Vision Pro’s battery life, there are still problems with the product.

“The apps and marketing pitch is awful even if it had 24 [hour] battery life,” he said. “This is not a painkiller. Platforms don’t become useful products. Useful products become platforms.”

Reviews of the Vision Pro have been pouring in since its debut.

BBC Technology Editor Zoe Kleinman tweeted that after trying out the headset, she had concluded that some of the technological features were “spot on” and a “game changer,” but other aspects—like its 3D content—were “weird” and a “gimmick.”

Other reviewers labeled the device “incredibly impressive” but “oddly lonely” to use.

Meanwhile, tech analyst Dan Ives of Wedbush Securities predicted that Apple would sell just 150,000 Vision Pro headsets during the product’s first year on the market, and 1 million in the second year. Comparatively, Apple sells more than 200 million iPhones a year, according to the Associated Press.