I've got some of that cement Geo. It's thicker than extra thin, but thinner than 'tube' cement, sort of in between the two.
I use it sometimes, but the brush fitted into the cap is too 'bulky', for want of a better description, so I was using an old, fine-tip paint brush, now replaced with the brush from an empty extra thin bottle.
It's good for those small parts, or joints, where a little more cement is needed than can be had from the extra thin, or where the extra thin might evaporate too quickly before joining parts.