The best Hammond clone out here. You can see NI B4 as a good-looking VSTi, but this has nothing to do with ANY other clone. Maybe, his only competitors are the KeyB Duo (another italian masterpiece) and the Hammond-Suzuki new B3 (if you can afford it). Probably, the best 50€ you can ever spend.
In general, I would say that GSI VB3 is the best clonewheel VSTi on the market. My only knocks against VB3 are 1) the overall volume output of it is lower compared to my other VSTi plugins and 2) It doesn't have a way to support playing notes above and below that max physical Hammond 5 octaves.