My hang up on Bixby is the same hang up that keeps me from activating any of the "voice assistants." I refuse to sign myself up to have my spoken thoughts submitted to someone else's server for their own purposes -whatever they may be- as a necessity of the service. Bixby is the very first one that I have actually kept looking into even after discarding it specifically because it is the way that a true automated assistant should behave.
I want to build things that use Bixby. I want to integrate Bixby into "things." I demand that Bixby run on MY own hardware, obey only MY commands, and do NOTHING that I do not explicitly train it to do.
No I am not going to send Samsung my location data. No I am not willing to send Samsung my commuter schedule. No I am not willing to send Samsung information about my eating habits. No I am not willing to send Samsung information about media that I like. No I'm not willing to let Samsung search for an answer without me explicitly telling it has permission to each and every time. No I am not willing to let Samsung "get to know me better" so that Bixby is a proxy for SAMSUNG rather than an avatar for ME. Replace "Samsung" with any vendor at all and it all works the same way for any of these assistants.
Google Assistant has been optimized to the point that the entire natural language processing network can run directly on device.
If Samsung can get that to work with Bixby and...I dunno...create a PAID version of Bixby that allows you to complete opt-out of all of the "product improvement" and "targeted marketing" experience, then Bixby is the one that will win.
As they stand, they are all losers.