Overall this one is very pricey for what you get. Yes it is a very good simulation of an ARP. And if the only goal you have in your mind is learning how sounds were made back in the heyday of analog synths you'll be happy as hell. It brought back some old memories the first couple of hours I got into it. The only problem is that nostalgia wears thin pretty quick, or maybe I've just gotten past love affair with analogs I had back in the seventies.
At any rate, this one has a very limited usefulness. Arpeggiators are common now, and you have to ask yourself why you want the ARP 2600. You aren't getting any sounds that you can't find in less expensive packages. The only thing you are getting is a very good GUI.
The real problem is that I use VST's for the sounds they produce and how useful they are in the music I'm trying to create. I don't really have to have a great GUI, and if the sounds are perfect I can even live with a pretty bad GUI. I wanted to like the ARP, I only wish it had something that could justify my buying it. I hate to admit that after installing it and using it (hours on end over a long weekend), I haven't found any use for it.
If I every need to create some nostalgic sounds from the seventies I might use it, but I suspect most people that buy it will find its capabilities limited (yes it is faithful to the original).
Before you shell out the money for it ask yourself why you are even thinking about it. If you always wanted to have an ARP but couldn't afford it, it’s a steal.
If you think you can use it for some of your music, I would suggest you get a demo of it and listen to it, then get a demo of Arturia's Moog modular... if you need retro sounds it would be a better buy...
The limited usefulness and high price make this one a very bad deal. If they ever lower the price below $50 it might be worth it, but in hindsight if someone stole my software and I had to replace it - I wouldn't replace it.