The Offero mug holds 16 oz or 20 oz if it is filled to the brim. My usual mug holds 12 oz. Although the Offero mug is very large and heavy, the shape of the handle is good and it made the mug comfortable to hold. The shape of the lip prevents the mug from being used for its intended purpose by someone who is left handed. I had to take some care when drinking because the extended top lip of the mug sometimes hit my glasses.
Today I brewed a pot of Sulawesi coffee and put the Offero mug up against my usual mug. The Offero received 16 oz and the other mug received 12 oz. i took five sips from the Offero and then five from the other mug until 12 oz were used from each mug. I could discern no difference in taste between the two mugs. Perhaps someone else with younger or more educated taste buds will have a different result. I will try this again with a different coffee perhaps an Ethiopia Harrar. For now I think it will be great for a cappuccino.