Ceramic vs Stainless Steel in coffee mugs
Stainless Steel

Most stainless steel travel mugs are double walled, but are NOT vacuum flasks

They usually have a screw on stainless steel base, or just a plain plastic base. Both of these stop thermal air losses, but are in no way as efficient as a true vacuum flask. It can't be anyway, due to the lid having a drinking hole in it

Lids with sliding covers are impossible to clean, and should be avoided. Just a simple double wall stainless steel mug, with a "reduced spill" style plastic lid and silicone gasket will last many years, be cleanable, and provide reasonable heat retention

Double Walled Ceramic

Double walled ceramic mugs are heavy, and while reasonable strong, generally have two fundamental flaws:


They are very heavy due to having two ceramic layers, even though both layers are quite thin
Because the layers are thin, most mugs do not have a handle, as they cannot support one without breaking


Their insulation qualities are fine and they can be-reheated in situ. The typical silicone lids they ship with are easy to wash which is a bonus

If you don't mind not having a handle they are fine, but heavy

I don't like drinking from silicone, it feels weird, and the hole is usually too small. Cutting a bigger hole always ends in disaster (maybe a hole punch would do it?). They also break much more easily than a normal ceramic mug if used while travelling