The silicone flattens down to almost nothing in my luggage, which sold me since I'm always short on space. Both bowls stay put in the vinyl holder so the water doesn't tip mid-drive. Used them on a two-day road trip and they held up great.
The bowls collapse flat enough to slide into my backpack pocket, and having food and water clipped together in one piece meant I wasn't digging around at rest stops. Rinsed clean at a gas station sink and they were ready for the trip home.