The thing is, I don't know enough about sous vide to know what an app would be used for. Is it just for reference temperatures? Or does it open up more settings than the interface on the device itself? It seems bizarre to whip out a phone/app to control a kitchen appliance. =)
The Original is $30 cheaper than the New Model in case you missed one of those or for other's sakes. I own the new model in red and so do a few others in here. I really like it. The app is finally out on both IOS and Android. If you care they are coming out with a Wifi model in the near-ish future. The current one is Bluetooth so the app only works from ~30 feet away.
I'd go with the bluetooth model if you can swing the extra $30 but the original is respectable if money is tight. If starting dinner from work or anything like that is important to you, I'd wait.
If you have any specific questions I'd be happy to answer any I can. I actually just vacuum sealed 5 pounds of chicken breast to sous vide. I used THIS. It works a lot better than I thought it would.
I've read that the older one has a more powerful heater and circulates water better, while the newer one has a better clamp and that app. Do I really need a bigger heater and that extra gallon of water? Is there really benefit in having an app? I suppose I won't notice any of these differences if it's going to be my first try at sous vide.