Interesting thread, the Kurzweil was the first keyboard I played that had a proper keyboard on it, was too rich for me back in 1991
Was quite impressive to have that much sample ROM to play with back then. Would be interesting to see how they've aged, most 90's ROMplers sound a bit thin now. I remember always lusting after a Roland JD800 (similar vintage) and after eventually buying it was disappointed that it wasn't as good as remembered, hopefully the Kurz' is still as good now as it was then. Still lust after a Korg Z1 but that's a different creature all together.
You are absolutely right. The problem, with 90's digital synths IMHO, is the abuse of the (back then new) internal effects, especially reverbs.
The JD-800 is superb for pads (and the JD-990 is even better) but if you listen to some of its presets there are tons of reverb, a wet/dry balance near to 60/40 or so and you will be really disappointed with how it sounds, especially these days, since our ears are now much more educated to what a nice reverb should sound like.
I remember JMJ in an interview in 1993 for the release of Chronologie saying the first thing he did when trying a new synth was bypassing the internal FX to hear the real sound of the machine.
Until Roland D-50, every synth had just Chorus and sometimes a simple delay effect.
D-50 and mostly Korg M1 started the internal effect revolution, but I feel Korg had better effects than Roland.
Kurzweil had a chip from Digitech, which I don't like too much, less flexible and less good sounding than the Korg effects. The K2500 introduced KDFX expansion to improve the overall quality and many users say there is no comparison (I never tried a KDFX).
Then, presets on K2000 were generally less hyped with the internal reverbs and more focused on the synthesis algorithms.
Anyway it's absolutely true, even in the 90s the first thing keyboardists were told in a studio was "hey, remove those effects from your keyboard, we're going to use our reverbs".
After listening to a serious studio reverb (like a Lexicon 224X or an AMS RMX 16 - to name a few) you really appreciate the abyss between those crappy internal reverbs and some luscious, deep, serious reverb...