This is for people who require portability epsilon percent of the time. If you never require portability then a desktop is sufficient. If you frequently requi

This is for people who require portability epsilon percent of the time. If you never require portability then a desktop is sufficient. If you frequently require portability then it's worth getting an air and building your workflow (if possible) around offloading heavy computation to the network, e.g. heavy use of build servers, SSH, syncing. But many people spend most of their time at a desk, but sometimes require portability. For example in a meeting, visiting a client, working from home occasionally, etc. For these people a heavy duty laptop is the best solution.