No, that is not normal. I've had several other devices including a Samsung Galaxy S3 before the Turbo and the Turbo signal is as good or better than any of them. Make sure you have your network set to LTE/CDMA in the mobile network section.
Did the speed test: It located PennTeleData as the closest in Palmerton, PA, which is actually 71 miles from me , but anyway, I got 31.53 mbps down and 6.60 up. and that is @ -98 dBm ...Not sure if that is average speeds or not. First one I did it gave me Philadelphia, which is way down south from me and got 9.19 mbps down and 7.49 up. Both locations ping is 70. And Add Scranton, PA Ping 397; 29.06 up and 6.68 down.