The biggest culprit on mine seems to be the H key with the double types or missed type. For the most part it is fine, However I have noticed it getting periodically worse during the course of the week I have had it.
I have a trouble ticket in with Verizon for a texting issue, they said if it is determined it is my phone, they will have me do an exchange....hopefully the next device is fine. I will ask to type on it to make sure it is nice and springy, this one is a little stiff.
For those that have the typing issue, are your keyboards also a little stiff? If you have no issue whatsoever, or yours nice and clicky? I wonder if the stiffness creates the issue a bit