Just as another anecdotal data point, my QC20i lasted 2 years, and then I tried to clean them, and the little metal grill went away. I thought it would be good to still have them, so I went to a local Bose store, and they were willing to fix it, which was pretty nice. I've had mine since 2015 and they've been around the world with me multiple times.

Agreed. I've had 3 or 4 of them over the years - great headset and in particular noise cancellation (airplanes, trains, etc.), but man, they break so easily. The plastic on the "brick" comes off, the little plastic ridge that holds the ear tips in place has come off on one side (so the ear tip falls off constantly), if you have the thing plugged in with the airplane adapter to the socket in your armrest and stand up, the whole 3.5 mm plug can rip off, the cable frays, etc. etc.