I ran some tests on Serato Sample. Because the Serato Time&Pitch full plugin is Mac only and crazy expensive ($800). So what does Serato T&P offer in Serato Sample?
Well first: It does NOT have a formant control or preservation (bummer - big bummer).
Second how does it compare: Reason's sequencer can time stretch as well, but not as convenient as doing it in a playable VST. But sound wise: SHORTENING - Reason and Serato T&P sound very VERY close. LENGTHENING - Reason takes on a growly sawtoothy character (nasty...), Serato sounds - well very natural, and the "spectral" sound won't come into play until you do crazy super stretching.
Since Serato Sample does not have formant control I have three ways of doing it:
Not tested. Antares formant or Ircam Trax formant (though I compared Ircam Trax vs VocalSynth2 previously and did not hear any difference large enough on natural vocals to motivate buying Trax (I have VocalSynth2))
Adjusting the formant higher - they all sounded good and very similar. You just need to set zPlane's Voicing control in the right range, otherwise it sounds weird. I guess Neptune and VocalSynth2 does this automatically inside itself.
Adjusting the formant lower - VocalSynth2 did not do a good job and got glitchy. On untreated vocals it works very well though. With zPlane's Voicing control dialed in it sounded OK, but Neptune was the best. Interesting.
So somehow when I tested formants on untreated vocals I put zPlane and VocalSynth2 one step above Neptune. But with the Serato T&P stretched sound, for some reason Neptune just likes that input and it sounded like the best with faster results to dial in.
If you play a range of keys in Serato sample you would then have to CV control the formant so it changes based on midi key. You can do this in all three plugins but zPlane will need you to CV two parameters.
Yes, Neptune's auto-tune will leave you wanting more if you have used Waves or Antares, but the formant control is quite good actually and previously I tested it against Little Alterboy and they sounded the same but Soundtoys has occasional nasty glitches where Neptune did not. So, kudos the Reason for this formant control. So yeah, I skipped Little Alterboys even at $29 for this reason.
As for chopping: Not perfect. Does not get the key correct every time. The Release control is wonky and no visualization as to how it is applied. To play a chop like a drum machine you need to manually set every end marker, in addition to fixing most start markers.
The Random is cool, if you have a long sample (like a box of chocolate !) And setting one sample to keyboard mode is super nice. Another key feature is: adjusting start markers on a loaded sample. This is where Reason gets is SOOO wrong. To do that in Reason, you need to go back to the sequencer and change the markers, split at markers, make a new Rex, load it into DrOctRex/Kong. That is madness. So, Serato Sample, despite it flaws, does make chopping much easier, and the P&T algo is very good.
You can play a sound in Iris2 and get it stretched and it sounds good as well, but it cannot do time stretch. So again Serato Sample doing BOTH time&pitch over a keyboard, well nothing that I have tested works this fast and sounds this good. So, there you have it!