But, a bigger vendor like Lenovo seemed a bit more trustworthy if I ever encountered hardware problems.

I thought the same... yet, I got disappointed by Lenovo.
As you know now, the detachable controllers have spring loaded copper pins. On my left controller, one of them fell out. I was able to plug it in and it worked again, for months no issues. Then it happened again, and I thought, hey I still have like more than half a year warranty, so why not get it fixed by Lenovo.
Nope, they claim I caused this and refused to replace or fix it for free. No matter what I told them, they stance is, this is a user caused error.
I could send it in for min. 35€ to have it checked, than I can decide if I want to get it repaired for at least 40€.
A new controller is about 70€.

Thanks Lenovo 😡

I bought a replacement controller when it was on sale, yet I'm disappointed by this service. I was one of the first to buy one, even from their store directly. Now I'm hesitant to detach the controller...

Yet, with the controllers attached and bazzite on it, it works really well, and I do enjoy using it from time to time.
I'm even thinking about getting an egpu for it. But from my experiences with bazzite on the ROG Ally where I have an egpu with their proprietary connector, I still had to use Windows to enable it and I wasn't able to get VR running on bazzite. That's why I have Cachy OS on the ROG Ally.