Ratings compiled by Best Reviews Guide place the Norpro 5569 Decorative Cup Warmer as the top coffee-mug warmer based on user reviews as of 2015. Rounding out the top three are Imperial Home's Desktop Coffee/Tea Mug Warmer and Norpro's Electric Beverage Warmer.
The Norpro 5569 features a nonstick surface over its heating element and a neon on/off indicator light. Amazon.com reviewers rate the product at 4.3 our of five stars. Reviewers praise the unit's heating power, noting that it keeps liquids hot for hours; however, some owners note that the Norpro does not warm cool liquids or that it takes a long time to do so, so its best use is for sustaining hot beverages.