They hold 8.5 fl oz which is just about the right amount of liquid for making lattes and cappuccinos, but they do need to be filled right to the top to get the right taste.
The glasses themselves are made of sturdy glass which is fairly thick - about the thickness of a standard mug. The heat does transfer through the main body of the glass so if you are making a drink straight from the kettle you would need to be careful not to burn yourself. However, the coffee machines tend to not make drinks at boiling temperature so although the glasses get hot you shouldn't burn yourself. The handle however does stay cold so you can easily pick up the glass when full.
The glasses wash well in the dishwasher but if washing by hand you will need to use a squeegie sponge as it can be hard to reach right down to the bottom due.
Just to sum up:
Pros: * inexpensive for two glasses * feel well made and good quality * sturdy, won't break easily * well balanced and comfortable to hold * fits under Dolce Gusto machines - I haven't tried other brands * hold just the right amount of liquid for lattes and cappuccinos * can be washed in the dishwasher
Cons * glass is fairly thick * if washing by hand you can't easily reach the base so need to use a squeegie sponge * literally holds just enough liquid for a latte, no spare room at the top * if adding sugar or drink doesn't mix you need to use a long handled spoon to reach the base of the glass