I've only been using it for a few days but so far I am very satisfied. I'm also glad I found the international version with the additional 2gb memory, and additional 128gb storage rather than the dumbed down version sold on most websites, Samsung's included.
It's got all the features I need and it's fast enough for my needs, it feels very responsive. It takes very good pictures for a cell phone but for someone that's used to a DSLR, no cell pone in the world will ever satisfy me.
I had zero problems making it work with T-Mobile, all I had to do was to insert the sim card from the old phone and my SD card, Worked right way.
I had been using Motorola's for many years and the transition to Samsung was not without quirks and weirdness.
You can customize the ring tone for your phone, for your email, for individual contacts, for whatsapp, for your calendar, and for many other apps. But Samsung apparently thinks it's OK to have the notifications be the same as the ring tone for text messages, so now, when my phone wants to tell me that there is severe thunder in the area I never know if it's weather or a text message. That's kind of annoying and it makes no sense.
Also I have not been able to find a comprehensive manual that explains what every single menu function does, not even in PDF form, they give you a bit more than the basics after that you're on your own. To be fair, Samsung is not the only company to do that. Still some of the menu items under "Settings" are not at all obvious as what they are supposed to do, and I as an IT professional with 35 years experience understand more tech than the regular individual. Again, to be fair, this is in part due to the mess that Google's Android techs have created.
Still, all in all I am very satisfied with the phone and will use it for a long time.