This series combines brightly illustrated phrasebooks and dictionaries with a summary of grammar ("How FrenchGermanSpanish Works"). There is no difference between the basic outline of the three books: classified lists of everyday phrases, vocabulary and illustrations are reproduced in each language: in Essentials, the traveller's requirements are everywhere the same.
The only concession to the different cultures comes in boxes called "Fact Files", scattered throughout the phrasebooks, which describe local customs to do with food, shopping hours, schools, favourite sports and so on. This confirms that football is the most popular sport in all three countries, that "heavy metal" is the same in all languages and that nobody in continental Europe eats a proper breakfast.
Phrasebooks do have their uses, provided they are taken as a supplement, not as a substitute for other forms of instruction. These three are attractive enough to mak you want to browse and dip, and small enough to slip into a backpack or suitcase for reference in emergencies. You should not expect much beyond that: it may be fun to learn to say "Ich bin wuetend ueber das Abholzen", and know that it means "I feel angry about deforestation", but it is not the same as being able to talk to Germans.
There are various pitfalls for those who rely too heavily on this type of aid. The authors try to indicate pronunciation and register, with a star beside slang and colloquialisms, but these are only crude pointers. In the French phrasebook, they err too far on the side of caution, classing innocent words such as branche (trendy) as "strong slang" that "could be considered very impolite". Not surprisingly, in view of that, the French for damn is given as zut! rather than the more common expletive.
Spanish does not even have a word for it, apparently - but Essential Spanish will not leave you at a loss when you want to say: "I'm not keen on scuba diving."
But, then, who knows what might come in handy?