Modern headsets sound great, and are so light and comfortable that they become an extension of your body. Using a headset seems much more natural than using a telephone handset. And it's certainly much more convenient and comfortable than squeezing a handset between your cheek and your shoulder while your hands are on the keyboard or you're trying to write a note. If you talk, while you write or type or use tools or read or walk or drive or care for a child, you should have a headset. Many cordless and cellphones and some corded phones have jacks for headsets with 2.5mm plugs, and don't need a switchbox.
Most headsets are comfortable for eyeglass-wearers.
A binaural headset will minimize the ambient noise that you hear. A noise-canceling microphone will minimize the ambient noise that the other person hears coming from your phone. Headsets with longer microphone booms will make your voice sound stronger, with less echo and less background noise, than headsets with short booms. Headsets with short microphone booms can be stored in a pocket or pocketbook, and are good for a quiet environment. Headsets with long mic booms make your voice seem louder, with less echo and background noise.