HTC One X had a poor 3G signal. But thanks to 1.28.707.10 system upgrade, HTC upgraded HTC One X radio baseband from 1.1204.90.13 to 1.1204.103.14. And it improves 3G signal reception. Wi-Fi signal is still the same on my HTC One X though.
HTC One X 3G Signal based on system update
1.28 | 1.26