I have the Exotic Percussions, firing them up as I write this.
They are not the most inspiring instrument I own. I find them well sampled, the interface is clear, I just find they have a difficult sound to connect too, especially for the music I write, which is mostly dark and modern. In general, since the instrument are not very well known or not very used, it is difficult to create an emotional bond with them, in a way a nice piano or string section would spark.
The instruments often have a short decay, which works well for arpeggiated sequences, I find. They are getting a bit too bright and harsh quickly, with lots of harmonics, the EQ works well in that regard. Stick a big long reverb after it (an external one) and you can get some nice textures easily.
I don't know why they bothered with the rolls patches, since the rolls go faster the higher the pitch. Not very usable if you ask me, or at least, not realistic.
There are some hidden gem, like the bowed patches, the first mallet is usually nice, and the repetition patches work well with the mod wheel. Don't hesitate to reduce the amplitude attack time. Totally different vibe. There is a kind of a transient designer as well (the "Shape" knob).
I might actually use one of the instruments on a project I'm working on!