Not sure if this is already mentioned here, but while surfing, I ended up in a site that has made a quality comparison for most known samplers. Also STS-4000 is there.
http://www.simonv.com/music/quality/index.php
I'm a bit confused about the results, as STS samplers have always sounded better to me or at least as good as any software I've had chance to try (apart from phase issues).
Samplers quality comparison
the 'difference' is about the same as a Miniscope versus Minimax comparison 
it's really easy to detect when you loop the 2 highest transpositions and a/b them.
the point of the comparison is restricted to artifacts of the sampler's synth engine when a sample is transposed - it's not about how trustworthy something is recorded.
They've intentionally used a pretty artificial task to detect flaws, BUT I SWEAR anyone would consider a (say) drumsample from the STS engine more 'beefy' if compared to the perfectly reproducing VSampler
Not to defend CWA's position, but THAT's exactly the reason people (still) spend a fortune for an EMU 1200 or a MPC60 today
cheers, Tom
it's really easy to detect when you loop the 2 highest transpositions and a/b them.
the point of the comparison is restricted to artifacts of the sampler's synth engine when a sample is transposed - it's not about how trustworthy something is recorded.
They've intentionally used a pretty artificial task to detect flaws, BUT I SWEAR anyone would consider a (say) drumsample from the STS engine more 'beefy' if compared to the perfectly reproducing VSampler
Not to defend CWA's position, but THAT's exactly the reason people (still) spend a fortune for an EMU 1200 or a MPC60 today
cheers, Tom