The power convertor/supply on most laptops get pretty warm. That's lost electric being given off as heat because the laptop batery is fully charged.

Leaving home and letting it sit plugged into the laptop not only is wasting electricity, but if an outage like a tree branch happens, the surge could take out the power supply and maybe even more.

At least having a plug strip would help save electricity and money, but also protect the equipment from damage.

Myself, I like to not only unplug the power supply from the strip,but the power supply from the computer and the lack of over heating the battery all the time helps it to last longer.