Was just in a strong 4G signal area last night near Okemos, MI and had -75 on the 4G with all bars displaying. Got 25 down, 20 up.
I agree with other posters. Despite the signal strength being displayed as abysmal in many cases, especially in low signal areas I have yet to drop a call or data connection. Everything works fine. Battery life seems to be the only thing to be concerned about with this issue.