Objective: Electronic nicotine delivery systems (ENDS), commonly referred to as "e-cigarettes", have grown in popularity, features and device types. This study explores how device type influences users' experiences and how experiences shape use behaviors, beliefs, and attitudes about ENDS. Methods: In 2016, we conducted 23 focus groups in 4 US cities with a total of 156 participants who were current adult ENDS users. We segmented participants by age, geographic location, and device type used. A moderator's guide was used to gather data on attitudes, beliefs, and use behaviors. Results: Discussions revealed commonalities between cigalike and tank users such as use to quit or cut down on cigarette smoking as a primary motivation and difficulty describing frequency and quantity of use. Distinctions between device users also emerged. Features that appealed to cigalike users included the simplicity of the device (eg, small size, ease of use); conversely, tank users described as benefits their ability to modify devices and customize experiences (eg, adjust the battery, nicotine level, and flavor). Importantly, users of both types expressed satisfaction with their device. Conclusion: The study found notable differences in attitudes and behaviors between device users such as valued device attributes, knowledge about nicotine concentration, and importance of flavors, providing further evidence that device type affects user experience.