Regarding musicianship, the Genos has absolutely improved my musicianship in several ways! For example, since there's no way to re-set "beat 1", I'm very much more aware of staying in time. Just to use drum fills requires me to know exactly which beat in each measure I'm on. When you play solo piano, it's really common to add or drop beats, add measures whenever you want, and play rubato without really meaning to. So with the Genos, my timing has really stabilized, and playing along to the various styles and rhythms draws out music that I never could generate by myself, without having the styles and rhythm to respond to. (I guess any arranger would do that, but Genos is my only experience with arranger kbs.)
Unlike playing with a band, I can keep one song going for over an hour if I want, and nobody complains or refuses to keep playing. That is huge, because I can explore different ways to play a song or chord progression to my heart's content. This has helped really get various chords and voicings, and creative use of scales, into my body, instead of just my mind. Just because you can understand the various aspects of music intellectually, doesn't mean you can actually play it -- until you play it over and over and over and over, until you don't need to think about it anymore. As someone who has spent countless hours playing exercises around the circle of 5ths, I can tell you without question, the Genos has made growing as a musician waaaaaaay more fun and productive (despite the big technological learning curve).
Also, learning to adjust and adapt styles to match the sound I'm after has really improved how I listen to music. I hear so much more, so my "ear" has greatly improved.
Regarding arrangers as cheating, or not for gigs -- I think Genos is great for playing solo, as part of a duo or even in a whole band, because it's versatile in how you can use it. Even if you just use the various voices to play leads in a band and to comp just as you would with a regular keyboard, it can be a great addition to any band if only for the high quality of voice sounds. Right now I'm exploring ways to play more meditative music for a local hospice house, using more of the synthesized sounds, strings, pads, etc. (BTW, would love to "talk" with any of you out there who are using Genos in this setting.) I don't imagine the bass and drums will be that useful there! But they sure will be with a duo partner and in a band, and solo, when I'm more confident in operating the computer aspects. The point is, you can still play the Genos as you would a regular keyboard, or add in the pieces that are missing, and that would just be like hiring the bassist, drummer, etc. (well, almost, anyway). That being said, when I do start gigging with the Genos this Fall, I expect to get criticism from other local musicians, especially when playing solo. So be it. Nice to be at an age in life where, who cares about a little criticism??!!