For several years I've used NI's B4ll clonewheel that's included with Komplete. Though I liked the sound of the organ itself, I've been deeply dissatisfied with the Leslie sim. The pitch modulation is way to pronounced for my taste. More like vibrato than doppler. To my ears it didn't sound any more like a B3 through a real leslie than the organ presets on my aged, wheezing, Korg Triton & I've been on the hunt for something better for quite a while now.
Thanks to Johan (Soulful Swede) my search has ended with the discovery of the Genuine Soundware VB3. This plug is 100% modeled, no samples at all! The organ tones are rich & clear & they nailed the leslie. It totally leaves the B4 in the dust IMO. There's a noise burst disabled (but otherwise fully functional) demo that I would definitely recommend trying first because the company doesn't refund purchases. If you decide to buy, they send a verification code that unlocks the demo. It's an Italian company so there could be as much as a 48 hr lag time before receiving the code. I got mine within 24 hrs.
Oh & did I mention the price.......50 Euros! It came out to a little over $67! (Your exchange rate mileage may vary.
My currency converter said it would be over $69.) Anyway, it's definitely worth a look if you're not happy with your B3 sounds (Even if you are. 
)Cheers,
Mike
