I've had an MK3S+ for years and even though it's a primitive machine in comparison to the current Bambu hardware I see no reason to upgrade to something else. It just keeps printing whatever I throw at it and the results continue to be very good. In fact, I seem to have better luck with it than the Bambus I sometimes use at various hacker/makerspaces.
If you just look at the numbers (speed, volume, ...) against Bambu hardware they're not as good, but the reliability and simplicity make up for it IMO. The main missing feature is multi-material support, but that's something I'm not really interested in due to how wasteful the current technology is.
But they cost more than Bambu. Most Chinese things tend to cost less than alternatives, for obvious reasons.
As a big fan of the company I'm hoping this will make them price-competitive to Bambu (or even considerably cheaper) while the tariffs rage. I'm not a fan of the tariffs, but if it gives a boost to the Core ONE launch, welp ... good for them.
If I remember what I saw during the day, and from recaps since then, it was only the Bambu Studio slicer (that is a fork of Prusa Slicer), which was provided with review units but without the source code being released yet. The code was released in time for production units. The only violation of the license is if they did not provide the code to reviewers when asked (which may have happened, but is not as clear cut as what their competitors imply)
It would be lovely for the BL printers/AMS to use a colour sensor at the hotend and then you can run a calibration on purges to determine what is an acceptable threshold when transitioning colours and use the absolute minimum purge amount.
I'm not using my AMS much, precisely because I simply cannot stand the waste and the additional print time.