Tech YouTuber Marques Brownlee provided a mixed review of Apple's first foldable iPhone, the Duo, ahead of its release. He praised its polished design but noted some "rough in the middle" aspects, particularly its $2,000 price point. The Duo is heavier and thicker than its Samsung competitor, a significant factor in daily use. Despite its bulk, Brownlee found the 4,900 mAh battery to be very efficient, lasting an entire day with over 30% charge remaining. The dual rear cameras are described as solid, though they lack optical zoom and perform less optimally in low light. A major drawback identified was the current app situation, with many not optimized for the foldable display. Brownlee concluded that while not for everyone, especially those seeking top-tier cameras or prone to breaking phones, the Duo is a fun device for those willing to pay the premium and embrace the learning curve. He highlighted the "fun factor" stemming from its polished elements like animations and the impressive hinge. Apple has done an admirable job with its first generation, despite inherent compromises of the form factor like slightly weaker battery, speakers, and cameras. Brownlee hopes for a second generation that addresses core feedback to create an amazing phone. Initial demand for the Duo was high, with estimated delivery dates extending into January. The success of the $2,000 Duo is crucial for Apple to demonstrate continued demand for its premium products, especially after the Vision Pro's poor performance.