Joey wrote:the biggest secret with arturia is that their emulations sound nothing like the real thing
I would say it depends on what sound you're after, how you use it, and where it sits in the mix. I'm finding that the biggest obvious differences show up with higher resonance settings and envelope behavior.
I've recently re-created some Voyager patches with Minimoog V, and can get close enough if it's not really high resonant all square waves, and it's not a performance lead. After adding effects and then adding it to the mix, I'm so far not regretting I sold my Voyager. The only thing I am missing is some really biting leads that VA just seem to fail utterly at, but then again, I suck so badly at doing leads that there's not much to lament over. To be fair, I'm not making a sound from scratch, and re-creating them is taking longer than it took me to make them in the first place. So it's not all wine and roses.
If you did nothing but performance leads and/or lots of real-time tweaking, I would say forget VA and get the real deal.