Perhaps your not thinking about the full offering, a laptop can use a docking station and provide a more comfortable keyboard, mouse, monitor experience, yet be flexible in the event you want to use it at the park for a few hours. I use a Lenovo daily at work in this configuration, it allows me to pop it out and take it to a conference room for a meeting and then dock for a workstation experience. This isn't going to solve the issues others will point out about hardware upgrades and things like that, if that's more important than mobility then you should go that way, in fact that's how I run my home computer.