Perhaps if I was just starting out, I might be more interested in Serum. However, I started out wanting to convert my MIDIs into metal arrangements. (That was before Shreddage was even a thing, haha.) So I ended up just ignoring all of the synths that came with Sonar X1 Producer, even though, retrospectively, they're awesome.
The only synth I really touched was Dimension Pro, and that's only because I bought the DSF World Instrument soundpack with it.