For basic cleaning, there's not much between the two types, but the plug-in model does have some general advantages. First, you can keep cleaning for as long as you want, and don't have to stop to recharge. Sure, some cordless cleaners provide power for whole-home cleaning, but even they will run out if you want to deep clean your house, tackle your sofas and car, for example. With a plug-in cleaner, you can just keep on going, and you run them at higher suction power for a deep clean. A smaller advantage is that you can generally use plug-in cleaners for other suction jobs as they don't cut out; cordless cleaners often (although not all models) have suction protection, turning off when they detect a blockage. For example, if you've got a vacuum drill attachment, where dust from drilling is sucked away before it can make a mess, this will work more easily with a plug-in cleaner. With a cordless cleaner, this kind of accessory may not work. Likewise, for vacuum storage bags, some cordless cleaners will cut out before you've compressed your bag; a plug-in cleaner will not.