While tumblers and thermoses are used for enjoying beverages on the go, high-quality travel mugs boast a variety of safety and convenience features that typically aren’t found in other options. Tumblers may be insulated and easy to drink from, but the seal might not hold up to lots of movement and jostling.Many thermoses boast a large capacity and impressive insulation, but they are less portable than travel mugs, especially those with a handle. However, some companies use these terms interchangeably, so it’s important to inspect the lid quality and insulation.