I guess to some point, my qualms with Bambu are that they haven't been around long enough...
But at what point, I asked myself, how long does a 3d printer company need to be around before I'll buy from them.
My answer is 3 years for myself. Others might have a different opinion. Further, if they dogfooded their own printers, I would have a change of opinion.
I don't think it takes 3 years. But the Mk4 has 1M hours in Prusa's print farm for Prusa to iterate on.
the other thing is that as a general rule, I don't buy the first model of <thing> when it comes out. I'll wait until v2 or v3 of thing.
With that said, I'm certainly looking forward to what the Bambu labs carbon x1 v3 looks like.