I've had this keyboard for years. In fact, I'm on my second one. I also had the stuck C problem years ago. I was thrilled when I found out that it was a result of the stuck function key.
My advice to anyone with the keyboard is to keep it very clean. It needs to be thoroughly cleaned often. I take out the batteries; use canned air and a damp cloth, and try to do a really through job. I pay particular attention to the function keys as they
do get stuck.
It also helps to keep an eye on the little switch in the upper right corner of the keyboard that switches the function keys form the blue to white functions. Sometimes that gets toggled when you aren't watching. (So key commands in say your word processing
program don't work.)
My only real complains about this keyboard is that it's easy to hit control on the left side when you need Shift and I need to think about holding down Shift to get caps. That may be due to my small, weak hands or poor typing skills though.
It does seem annoying that I'm still reading about people who've spent a lot of time and frustration on the stuck cap issue after all these years. I recall how annoying it was and how long it took me to find an answer. Given that it remains an issue, I suppose
it's hard for Microsoft to correct. But I think it would be a good idea to put something in the start guide with the keyboard warning users that it needs to be cleaned regularly. Most of us have experience with keyboards that work for years even when almost
crusted over with dirt, grime, and grease. This keyboard really is a bit of a prima donna as keyboards go. Warning users of this up front could save a lot of grief.