This is cool stuff and can sound fantastic, but the key word, "can".

This confused me for so many years. Why did so many of these expensive VSTi instruments sound so bad when I inserted these on a simple midi melody track

I came to discover that, as it says on the web page:

Availability of the physical controllers, most importantly an expression pedal or breath controller, and mastering real time use of the most important controllers are the key."

Pay attention to the phrase. "mastering real time use of the most important controllers

MIDI which has not taken these controllers into account sounds like a circus organ no matter how fancy and expensive the synth. But you guys already know that. grin

BIAB – 2025, Reaper (current), i7-12700F Processor, 32GB DDR4-3200MHz RAM, Motu Audio Express 6x6 - My SoundCloud (Tip: No need to create a SC account to hear music - just hit ESC ).