I own both the JP-8V and one of the later JP-8As with DCB port.
I tried to recreate one of the JP-8V patches, I believe it's called something like 'CELM_Heaven's Pearls' on the real JP-8.
Of course, the JP-8V has effects built in, and the Galaxy module. So I disabled those.
I was able to come very close, but not exact. As you can understand, the fader and knob positions on the JP-8V are visually different than what had to be set on the real thing. Especially the portamento (there's a tiny portamento on this patch) and the Fine tune of the 2nd VCO.
I had a difficult time getting the filter slope and the filter envelope on the real thing to sound like the JP-8V. It had to do with the decay of the envelope. For a while I thought I should set the filter to 12dB / oct, but I eventually got the patch to work better.
Personally, software synths aren't really my thing but I find the JP-8V to be very inconvenient to use for a couple reasons. The graphic controls on the JP-8V are tiny and hard to see. With all due respect, the actual physical look of the keyboard is less important than the useability of the software. Arturia should allow the user to resize the graphic screen.
Secondly, the real JP-8's portamento is adjustable in real time. You can set the JP-8V portamento very slow, play a chord in poly mode, and change the knob but the speed of the portamento does not change when you move the knob. So it's not "just like" the real thing.
I don't consider software synths to have the same performance value as a piece of hardware. There is just something about being able to reach out and touch the control, to have the thing in front of you. Playing the JP-8 feels like being in front of a spaceship console. That alone impacts my mood when I play it and it evokes a certain response.
The real JP-8 also doesn't crash with Windows (it doesn't care a hoot if the computer crashes), it doesn't require an update to work with your VST host. It doesn't need a dongle or Syncrosoft copy protection, and it doesn't tax the computer's processor down to nothing.
I consider the Arturia JP-8V to be an instrument in it's own right, but not a 1-to-1 replacement for the JP-8. Arturia is marketing it as such and I think that is probably a bad idea.
That said, Arturia did a good job on it for what it is.