I see a few comments about the X having both synth oscillators and sample oscillators, and thinking only sample oscillators would have been better... I initially thought this as well but when thinking about it, this configuration is one of the things that will set this hybrid apart... why?
1. You can obviously audio rate modulate the two with each other... only few synths have had that option, like the Yamaha SY/TG77 for example.
2. You can create less "stale" sounds when having a pair of synth oscillators on top of a sample that normally trigger exactly the same at each keypress... this is one of the reasons that synths sound more organic... the constant running oscillators... but in addition to that, you can create the typical D50 type sounds with it... the D50 used small sampled transients, and combined these with synth oscillators that did the sustain part... it opens up lots of 80's inspired sounds because of these extra synth oscillators.
So I do by no means consider the synth oscillators as a "bonus"... they are as vital to the flexibility of the Profet X as the sample oscillators are in my opinion expanded quite a bit on both the amount of sounds it is capable of creating, as well as making those sounds more lively and organic... samplers with only sample oscillators can get quite stale and static sounding. By having the synth oscillators you can create these types of sounds without having the need of layering it with other synths, and you can save the sounds as an integrated sound... i like that idea really.