Yes, they are included. I don’t know Combustion but particular effects in AE need some customization to get the entire “visual power”. They aren’t 3D effects except ‘CC ParticleWorld’ and ‘CC Particle Systems II’. But if you want maximum from AE I think you have to get Trapcode Particluar, a great 3D particular system.
If you want to see an example of AE’s Particle Playground, download this MOV file from this link:
You can use Particle Playground, Foam or CC ParticleWorld (a Cycore effect in bundle) to have some spectacular effects. They need customization. Particular plug-in its esaier to use.