I started with an UM S3 last year, easy to setup and great performance. But I kept seeing the X1 Carbon pop up on videos. I pulled the trigger last week and my X1 Carbon + AMS has arrived. It's fast!
The BambuStudio software is much better, easier to use, (at least for me. I understand it may or may not be as customizable as Cura. But it works). The Bambu software lets you "paint" so it's super easy to use all the different colors or materials in your AMS.
But, the known issue with the Bambu is it poops... a lot! My first print used a PLA and a support material and had nearly 1000 material changes. So it would print, purge, print, purge. It's a lot of waste. There is something to be said about dual extruders on the S3.
I am still learning it, and I believe the purge can be calibrated and adjusted for less waste. But I haven't gotten there yet.
The downside of having both printers is different filament sizes. But i'll keep both for now and keep messing around.