I bought this as part of Arturia's V2 Collection. Because I never got a chance to play with the original hardware version, I can't completely vouch for the authenticity of it's sound. But since every other Arturia TAE based VST seems to hit the nail on the head, I have no reason to think it sounds anything other than authentic.
The previous reviewer focused on value for the money. I don't totally discount what he says, but since I got it as part of the collection, I don't feel any buyers remorse. That having been said, if I were to buy Arturia VSTs one at a time, this would have been more towards the bottom of my list. Not because it's a bad looking or sounding VST, just that I've never really spent a lot of time with ARPs over the years when compared to Moogs.
Still, there's a lot of flexibility to be found in this VST. The 2600 was a "partial modular" synth which means that it wasn't as flexible as a fully modular synth, but it had more flexibility than the hard wired OSC to VCF to VCA signal chain that most every other synth comes with.
In the end, if you get this VST for nostalgia reasons, you won't be disappointed. If you get it for sound, you won't be disappointed. If you're looking for the biggest bang for your buck, then search a little more.
The previous reviewer brings up a good point. With this and ANY other VST purchase, download the demo and play with them extensively before spending your hard earned cash on them. Since this came with the collection, I'm a happy owner and glad this VST is part of my arsenal. If I lost it somehow though, I'd replace the others first before I'd reinvest in this unless it was in a collection as was the case for me this time.