I was fortunate enough to beta test & write a demo track for Blue3, and was very impressed by the wide range of useable tones. If you have time, take a listen to the full demo track "Eyes Open" - all the organs & rotary in the track are Blue3 + some additional reverb and delay for placement/space http://www.gg-audio.com/#listen
(btw, all feedback on the song is very welcomed!)
I own a lot of organ VST's; Native Instruments B3 & vintage organs, AcousticSamples B-5, SoundDust HAMMR+, Omnisphere's Organs, and I tend to use all of them when I write as they each bring something unique to the table, but since using Blue3, I've found it a very worthy addition to my arsenal as it brings a unique and powerful voice of its own. Its currently my "go to" organ, especially given its really small footprint and wide tonal options! Very impressed by this release, and from a brand new developer to boot! Looking forward to seeing what else they come up with.
p.s. if anyone wants the sounds I used in my track "eyes open" I saved every organ used as presets. I believe I used 10 organs in total (maybe more?) and would be more than happy to share them with anyone who wants them. Just send me a PM.