Over the years I have accumulated a number of East West Libraries. I also have SampleTank, Kontakt, and Miroslav Orchestra. I rarely use them. The East West libraries are my main resource and I have been very happy with them.
Mind you, sample libraries are what I enjoy. I do not use Synths very much at all. Goliath was my first EW library and I still use it fairly often. In some instances I have preferred a Goliath sample to one from the more specialized Libraries.
The East West libraries I find least useful are Fab Four ( really only for Beatles Fans ), Voices of Passion ( there are better vocal libraries out there ), and Gypsy. When Gypsy came out it had the best solo violin and many bought it for that. Now there are better solo violins at a better price point. Of course if you like Gypsy instruments it is a great library.
It is all a matter of personal taste.