[AT&T Samsung Galaxy S7 Edge Guides, News, & Discus] Symphony0fLife:
Another interesting development! You can flash the firmware from the U model of the S7 Edge to the AT&T model. Do not know if this is possible for the T-Mobile, Verizon, etc. models. It should be. If anyone tries it and finds out, let me know and I’ll update the post accordingly.

Edit: Root is possible using previously posted method for 935A. Working on a method that doesn't require the engboot file for the U firmware but no promises yet.

The major advantage here to some will be that there is less bloatware. There is zero carrier bloat. None. Nada. Zip. The Samsung bloat is still there, however you can uninstall (yes, uninstall, not disable) most of it. There are 4 it seems that remain and can’t be uninstalled. These are Samsung Pay, Galaxy Apps. Clock, and Calendar (S Planner).

The menus are different. I think the menus are an improvement to be honest. Everything is there aside from the AT&T specific stuff (since this is the U firmware, it's not carrier specific). If you rely on AT&T specific items/bloat, they are not present here.

Frequently asked things I have tested:

Hotspot – Working fine here.

Samsung Pay – Bit the bullet and tested because I knew it would be asked, even though I don’t care to use Samsung Pay. My device was rooted previously. I flashed this and am no longer rooted. Samsung pay works fine. Tested it at the store this morning.

IF YOU HAVE A DIFFERENT EXPERIENCE PLEASE UPDATE ME, AS THIS SEEMS TO BE THE MOST ASKED QUESTION.

Update - I have now heard from 7 other users besides myself confirming that Samsung Pay works in store and haven't heard a single report of it failing so far. I'm now confident to call this working across the board, however do keep in mind there's always a risk.

Everything else seems to work as normal. User experiences are different. You may use things that I don’t, so you may find something that’s broken. If you do, please let me know and I’ll update this post for everyone. Please note the firmware also installs Instagram and Whatsapp by default in addition to Facebook, and they are both removable. Facebook however, much like on the AT&T version, is not. You can still turn it off though.

How to install:

Put your phone in download mode.

I personally had success with this version of Odin: http://www.mediafire.com/download/2t2sjqxtogbkafk/odin_3.12.3.rar

However another user couldn’t get it to work and used this version: http://d-h.st/gsDA

Flash the 4 files in this zip to your phone using Odin. All 4 of them: https://www.mediafire.com/?fm3oxddajta1k07

Put the BL in the BL slot, AP in it's slot, and so on. Flash all 4 at once through Odin.

When using the second version of Odin, I encountered an issue where the phone would crash during setup just after the wifi screen. If you have any problems with either, please report back and let me know. Either way, this seems safe to try on the AT&T version of the S7 Edge. I am able to go back to the stock AT&T firmware I’ve uploaded in my other thread just fine. So if this doesn’t work for you, it’s possible to go back. I have went back and forth 4 times now, and met with success going to and from the stock AT&T firmware to this one each time. However as always, try at your own risk.

Again, since many people are asking about carrier specific features - This is the SM-935U firmware. U meaning unlocked. It's not carrier specific. Anything AT&T does to modify the firmware WILL NOT BE PRESENT.. Use this solely if you want a more pure Android experience. No carrier bloat, being able to remove almost all Samsung bloat completely without having to root to do so, and getting updates before carrier specific models. If you rely on AT&T specific modifications to the S7 Edge, this is not for you unless/until someone finds a way to add them (which then defeats the purpose of the U firmware, meaning you might as well stick to the stock firmware).

FAQ

1. Does Samsung Pay work? – Yes. As long as you don’t root the 935U firmware (which is possible using the method currently available for the 935A) Samsung Pay works fine.

2. Does it have Enhanced LTE? – No. Enhanced LTE is a carrier specific feature. This is the U (unlocked) firmware. Anything unique to any carrier is absent. Period. Confirmed by testing against an actual SM-G935U.

3. Does it work with any other carrier than AT&T? – I have had people reporting success with T-Mobile and Verizon versions of the 935. I do not have one, so going from what they say – it works, but attempt at your own risk or search for their posts and ask them personally.

4. How does it perform compared to the 935A firmware? – It benchmarks noticeably higher. It also has a measurable advantage in terms of battery life. It performs better stock than the 935A rooted and tweaked, and when the U firmware is rooted and tweaked, it performs even better still. It’s all around superior to carrier specific firmwares.

5. Can you uninstall the Samsung bloat? – All but 3 apps. Yes, uninstall, not disable, and no, you don’t need to root the U firmware to do it.

6. Can I still revert back to my stock firmware? – Yes. If you have the stock firmware, it’s easy to flash back to it. It won’t trip knox or break Samsung Pay.

7. Will you be modifying it to have the AT&T features? – Likely not. That would entirely defeat the purpose of going to the U firmware. If you want the carrier bloat and features, you’re ahead to just stick to the carrier firmware.

8. Does this work for the regular S7 or the S7 Active? – I have no idea. I don’t own either phone, and cannot test it. I’m going to assume not. If you are brave and test it, do let us all know.

9. Do you have access to the S7 flat or S7 Active U firmwares? – No.

10. It shows the security patch from May. Is it out of date? – As of 7-7-2016 I have an actual 935U as well as my 935A with the U firmware. Neither has an update currently, so it seems the May security patch is the latest out for the U model so far. If I get an update on my actual 935U, I will let you know if it shows on the 935A with the U firmware or not.

And for those wondering about all the U files floating around...

Here are a few screenshots. I hadn’t installed all my stuff yet, however I had uninstalled several of the Samsung bloat apps already.