This was posted in German Musikerboard. It‘s from Greece and from 2019. I don‘t know why they called it PC4 contest, as apparently only PC3s including expansions were used. Anyway, it gives an impression of orchestral sounds. I hope it hasn’t been posted here before.
For iPad/Mac users who don‘t see the embedded video, this is the link:

https://youtu.be/cXJcPLUQhis

I have to admit to always having been a huge Kurzweil orchestral sounds fan, to the point that I bought a horribly expensive K2500S and loaded it it up with all the orchestral and piano expansion ROMs and put in the pricey KDFX effects expansion back in the day (round 2000, if I can remember that far back!).

For the time, pretty close to state of the art, and I did quite a lot of arranging work with it. But the writing was on the wall. Even at the time, samplers were starting to outgun the Kurzweil’s if you had enough of them, and computer libraries were getting pretty big.

Nowadays, computers have got to the point of virtually indistinguishable from real orchestras, at prices a fraction of what a fully loaded Kurzweil costs. And the cherry on the cake is how modeled horns have finally got how saxes and other wind instruments sound like as they go from note to note, which I’m sad to say is what makes these performances so dated. Listen to some SWAM modeled saxes in the hands of good demonstrators (you can still kill even the best modeled horn sound with a bad performance!) and it quickly makes those Kurzweil’s sound so ‘last gen’…

I still love my Kurzweil, it can do some things that are still up there with modern keyboards. But emulating horns ain’t one of them!

I don't like the vibrato and bending of the sax, and I'm not fond of the big band brass at all. The other sounds, especially the strings, are nice. Of course, as you say, not competitive to software libraries.

The thing is, Kurzweil’s have a breath controller input (or at least my K2500 does, not 100% sure about PC3’s). You can do some pretty realistic stuff with one of those.

But I truly believe that 99% of it is still down to the player. You either think like a horn player or you don’t. Most keyboard players go ‘close enough!’ and leave it at that but discount how familiar with great horn players even the average listener is. Close enough isn’t close enough! You either nail it or don’t bother. So many other sounds are easier to play. The wrong vibrato, the wrong bend, it doesn’t matter how good the basic samples are…

For me, one of the strengths of the original Kurzweil orchestral expansion programming was the multis… There are a ton of presets that put close to the whole orchestra on the keyboard, and with clever use of foot switches, buttons, expression and sustain pedals and velocity you could on the fly orchestrate and move between combinations of sections. High strings and oboes move effortlessly to cellos and brass, then a nice tutti with a piatti cymbal clash. Or whatever you felt like. And seamless multi changes as you moved from one combi to another.

Not many computer orchestral libraries offer this ease of use playing live (understandably) and comping together a quick rough orchestration….