Forget the bars...look at the signal strength.
My new S4 shows -77, my wifes S3 -85 and my Note II -93.
Best signal strength goes to the S4 in my neck of the woods at least
If they are updating towers around you, you will have issues. Also they don't work on all the towers at the same time on the whole town, they do them one by one, maybe your brother is in an area that either has finished with the updates or is next in line. Also the work on a tower will take some times, and after that, is not that you will have excellent service, but my suggestion is to keep doing PRL updates, just in case they start turning on new towers.
My bars are less at home than my Samsung Epic showed, but even with no bars, it seems connected - - works ok. Hope you are worng about connectivity problems . . . .
I've been with Sprint for 10 years and lived in the same town basically my whole life. I have never had any sort of reception issues in town. My Galaxy S4 has been roaming the past 2 days. I can't take calls and my text messages have been bouncing back to me periodically as my phone goes in and out of roaming constantly. I know they are updating the towers in my area, but other Sprint users I know that are in the area (including my brother who has the HTC One) are not having these same issues. I DO NOT WANT TO HAVE TO RETURN THIS PHONE. I absolutely LOVE it. I know some are having these same issues with the S4, but surely it doesn't have the worst reception of any phone that I've EVER HAD does it? Say it ain't so..