My main issue has been the “too snug” a fit for bigger spools, especially Prusament - I have a lot of Prusa filament as I moved from a Prusa Mini to the X1C, and to be quite honest, I love their filaments - so that’s the main one, and it’s all about the too narrow slots. The other issues I’ve had with Bambu spools have been when they are less than 50% full - they appear to be too light, and they just get pulled up into the lid, and then we have horrors.
I’ll be fair - when the AMS works, it’s a delight to behold, however I can’t do without my prusament working !!! 
Fingers crossed for the Hydra, and any future improvements from Bambu themselves!