I've also been following Nubi since the early days and though those early betas were already good the most recent updates have really made it formidable competition for B4. First thing is first, the sound: frankly I've played with B4 quite a lot and also own DaOrgan and in the raw sound department Nubi beats them both. It just sounds more organ like and present than either of those with great sound throughout the length of the keyboard. The leslie (rotary chorus) isn't a perfect emulation just yet but as of the most recent update holds it's own with most leslie emulations available in VST format. Now on to features, Nubi is without a doubt the most flexible organ emulation allowing you for control of the foldback points, multiple types of percussion, tuning scales, percussion harmonics, drawbar leakage, etc. If that wasn't enough there's more to tweak in the config file, that PJ didn't want cluttering up the GUI (which was smart as these features are already more than enough for most). The only reason Nubi didn't score a perfect 10 here is due to the lack of vibrato which I'd personally love to see implemented in the future. The GUI is a good size, easy to read, and has just the right amount of features present, so another big score there. The User Guide is a .txt file which covers all of the features and explains them very well. Nubi get's a low score in the preset department though as very few are available, but the real fun in Nubi is coming up with your own sounds anyway. PJ is great as far as taking care of his customers whether it's a technical problem, or feature suggestion, etc. And finally for less than $40 I can't see how you can go wrong with Nubi, check it out.