[Sprint HTC One (M7)] AlanGarcia561:
I will tell you guys how I did this after much struggle including some details not mentioned on the guides:

First, make sure you have a correct ADB and Fastboot conection using the commands "fastboot devices" & "adb devices", and that your devices are shown correctly. Try and only use USB drivers "HTC_BMP_USB_Driver_x64_1.0.5375" & "UniversalAdbDriverSetup" found all in one nice package here: (Thanks BD619)

http://xdaforums.com/showthread.php?t=2244060

I was under Hboot 1.56, and you HAVE to get S-OFF, which is pretty easy to do using Firewater under Hboot 1.56:

http://firewater-soff.com/

Firewater worked for me, try that first before other options to get S-OFF... if you are on Hboot 1.55, then use runrummer (most people say it's more successful):

http://xdaforums.com/showthread.php?t=2618524

If you are on Hboot 1.56 and S-OFF, then you will have to downgrade to Hboot 1.55 in order to be able to use the proper RUU version, by simply flashing this file:

http://xdaforums.com/showthread.php?t=2565201

HOWEVER, after flashing that file, it seems that the drivers that work for Windows 8.1 machines, won't work anymore under fastboot, so I had to install a fresh copy or dual boot one of Windows 7 (preferably 64 bits), in order to avoid ERROR 155, and others...

So, by now, you have Hboot 1.55, and you are ready to flash the RUU :Sprint_HTC_One_m7wls_1.29.651.10_RUU.zip. Remember to ALWAYS relock the bootloader BEFORE using any RUU, regardless of having S-OFF.

After relocking the bootloader, use this RUU:

Sprint_HTC_One_m7wls_1.29.651.10_RUU.zip

Now you can finally unlock the bootloader again, flash TWRP recovery, and gain root again in order to follow step 3 of the SIM unlock guide (the package by BD619 will be useful for recovery and root).

After rooting, look at step 3 of the SIM unlock guide...

http://xdaforums.com/showthread.php?t=2586704

Right where it says:

TIP: the app made by viperboy does work correctly under this RUU, just follow its directions.

After unlocking correctly, you can update your sense ROM... I suggest using the BadBoyz ROM with Sense 6:

http://xdaforums.com/showthread.php?t=2694171

Now comes a tricky part... that is, setting your correct APN settings, and catching that carrier signal for correct voice, text and data...

PATIENCE IS KEY!!! If you don't have patience, stop here. Otherwise, look at this short video to find you carrier's signal:

https://www.youtube.com/watch?v=VmwSlLXnfLA

Look towards the end... the settings under Settings - Mobile data, should be:

Network Mode: GSM/ UMTS only

Allow GSM data - checked

Available GSM networks: T-Mobile in my case

As for APN settings, go to Access point names to edit, or add APN settings. As for me under T-mobile here in Florida, only these work so far:

fast.tmobile.com for LTE does not seem to work for me, so I am still looking for other APN settings that will give me LTE.

Final notes: I'm too lazy to check if I will be able to get LTE at all on T-Mobile (have to check if frequencies match for this phone and that carrier, doubt it, and also, too lazy and scared to mess around with downgrading or changing the radio version, need more research).

This thread looks interesting, but idk if it applies at all to my situation since I don't get dropped signals:

http://xdaforums.com/showthread.php?t=2647305