Andrew Cunningham at Ars:
Here’s our biggest problem with the new iMac: making a laptop thinner and lighter is immediately noticeable. You touch and move a laptop constantly. Not everyone wants a laptop that values its size and weight more than, say, a faster processor or larger screen. But we can all at least agree that there is a very real place in the market for those thin and light devices, just as there’s a place in the market for gaming laptops or budget laptops. To achieve a more portable laptop, compromises like a lack of an optical drive or user-upgradeable memory are acceptable and even desirable.
In a desktop computer, though, the pursuit of thinness at the cost of features makes less sense. The vast majority of the time, it’s going to be sitting on your desk, and users will be interacting with a separate keyboard and mouse, pausing only occasionally to plug something in or adjust the screen’s angle. Giving up desirable features like user-upgradeable RAM just to make a thinner desktop seems like the wrong move, even if it’s one that only IT people and power users will notice or care about.