There will always be arguemnts as to what Vangelis uses on tracks, but one thing is for sure - the CS80 is not all he used.
He used Fender electric piano's, Yamaha CP piano's, and GS1 FM synthesisers. If you are a Vangelis fan, and you need to recreate his pallette, you will need VST's that emulate these sounds as well.
If you compare the track you mention to the Blade Runner soundtrack, you can hear similar sounds, and I would say confidently that none of those piano sounds some from the CS80. You can get similar tinlky sounds from a DX7 that sound like the GS1, and to some extent Fender Rhodes electric piano's. I think you will be well served with an FM based VST - like Native Instruments FM8.
The CS80 was used for pad and string sounds, and of course the famous leads, but it was not his only instrument! It lacks the necesary modulation capabilties that some of the last analog synths had (eg JX8P, Matrix 12,6) that allowed them to compete to some extent with the new FM synths - and produce 'piano' like sounds.
By the way, The VST is not that bad - who can afford the real thing anyhow?
If you want the sound of the CS 80, then you will not get it from the plugin. There is no great honour in copying somebody, but doing it badly is deeply unnecessary.
I'm always shocked at the great reviews given to Arturia products.