Project5 is most definitely focused on making music from scratch or samples. It has many virtual DXi instruments, 7 in total. If you install Sonar this means you have 10 in total, more than enough for most people! You get Dimension (sampler), PSYN II (analog synth), Roland GrooveSynth (Roland emulator), DS864 (sampler - can use AKAI samples), Velocity (sampler for drums), nPulse (another analog synth), Dynamic Arpeggiator (creating trance style sweeps) and also Alias Factor (more of an audio plugin to add effects). The audio quality is excellent. The large range of sounds available should hopefully ensure that musician is catered for. A word of caution however, soft synths do eat up CPU power, so lots of memory and a fast CPU (maybe even dual-core/processor) is necessary for running many tracks. But it is still cheaper than buying dedicated hardware samplers etc.

My favourite was Dimension which has over 3GB of sampling data, and many instruments. One of the piano samples alone is over 200MB, but it took a couple of seconds to fire up. Dimension is also very fully featured so you can edit the sampler settings very comprehensively.

It can be used as a standalone audio/MIDI sequencer and is quite fully featured. It's quite easy to use and feels a bit like Fruityloops. But Sonar is far more fully featured in this aspect. However, Sonar does cost a lot more! You have other features for live use such as the GrooveMatrix, which can be used like a pad, triggering sounds. It supports ReWire both as a host and a client (I only tried using it as a client with Sonar as a host).

It makes a good compliment for Sonar. In addition, if you prefer you can use Project5's DXi instruments directly in Sonar without using ReWire (I prefered this, as it's a lot easier to use), channeling Sonar's MIDI output to one of them DXi's. If you do choose to use this on its own, it's still very well featured for music making, but you will lose the great audio plugins Sonar has to offer.