I knew the iPad Air would be lighter but I didn't expect there to be this much of a difference. It's kind of like the difference between and old car full size cars from the '70s and the sleek, aerodynamic cars of today. The iPad 4 is solid and has some weight to it. I have no complaints about it. Has worked great for the last 2 years. The Air 2 is much lighter, sleeker and physically smaller. I haven't experienced any screen distortion (I'm using a Smart Case) but the first thing that I noticed was the speaker vibration. It's like having a subwoofer with a screen attached. That was noticed while playing Real Racing 3. The graphics playing that game are noticeable better. No lag and sharp details. Another thing that I noticed was when I had both iPads on my bed and I could see the ceiling light in the reflection. There was less of a glare on the iPad Air 2 (I know the screen is different). The color of the light looked different in the reflection. More of a darker blue than a bright white. Last thing that I've noticed so far, WiFi speed is much faster. 120-124Mbps vs about 50-70 with the 4. So far I'm happy with the purchase. The speaker vibration will take a little getting used to and I'm going to miss the solid feel of the iPad 4. That feeling might go away after a few days.