I love the Model M, and have not found another keyboard as good. I'm using a Unicomp now, which is close. (They had a previous model whose keys were flaky, occasionally failing to produce output. But apparently they have fixed that problem, and my current Unicomp works well. I think it is 2-3 years old.)
I actually have a few Model Ms, but I have become reliant on the "windows" keys, which the M lacks.
My Unicomp Model M (Date: 2/25/2020) had 8 key caps that didn't feel right. They worked but there was too much wiggle when fully depressed. I replaced them from my previous UMM (Date: 1/4/2007) keyboard which had developed a couple dead keys.
I actually have a few Model Ms, but I have become reliant on the "windows" keys, which the M lacks.