Honestly, with the introduction of the custom wake words, I have actually switched from Gemini back to Bixby. It's the simple things that it does so much better, like setting reminders, timers, and even just navigating to destinations.
If I tell Google to take me to Emily's house, it will try to take me to the Emily Dickinson house, whereas Bixby will check my contacts, see that I know someone named Emily, and then put in their address. It's something that Google used to be able to do, but Gemini cannot seem to figure it out.
Honestly, IMO the fact that Bixby is generally a little bit behind the Google Assistant and Gemini is actually a good thing now because the Google Assistant has gotten so advanced that it's now just useless.
