IPhone OS 2 Apple II and Mac as one of the great revolutions in modern technology. It takes it beyond simple Phone + iPod, or even smartphone, and makes it the leading contender for the next great shift in computing." However, they criticized it for having stability issues and overall sluggishness. "Macworld" said, "The iPhone 2.0 software is full of the kind of refinements that you’d expect from a second-generation Apple product. The iPhone OS still isn’t perfect, and we wish Apple has addressed some lingering shortcomings, but it’s a welcome step-up for what was already arguably the best mobile platform on the
IPhone 3GS more favorable reviews mainly because it comes pre-installed with iOS 4. Jason Snell of Macworld praised the iPhone 3GS, saying that "the device's internal changes shines in the iOS 4 update, making the iPhone 3GS a worthwhile upgrade compared to its predecessor although a little too late compared to the iPhone 4." TIPB stated that "aside from hardware specific features like FaceTime, Retina Display, and gyroscope support, the bottom line is iPhone 3GS users are getting the same software that makes the iPhone 4 great." Shortly after the release of the iPhone 3GS, some users reported overheating of the device