Don’t be fooled someone inside Samsung made mistakes, stuff happens, but dont switch to the other guys yet. I use an Samsung S3 for software development, and never had problems, I travel with a Samsung S5, works like a rock and we own a Samsung J7 Dual Sim we use for your travels to Brazil and back, if you have a family member that travels a lot, this is the phone to have.
Once you insert the the two sim cards inside the phone, and program the SIM Card Manager, all work perfect when the Pilot tells you to turn off the phone you activate the SIM card manager for the final destination, and voilah. Once you land in your destination and turn your phone back up no worries, all working fine.
Note for Metro PCS users: we have our account with this company and the Samsung J7 Dual Sim is not on the list of approved phones they will activate, so I strongly recommend when you call to activate do not give the phone operator too much details about your phone make and model, once you give the IMEI number to the operator the phone will activate normally in the Metro PCS, works like a charm.
I do not know about the other carriers, but I would think it is the same case, less is more. Yes the processor of the J7 is not the latest, but I can tell it wont catch on fire, has a large screen, battery would last the whole day, comes in Gold, has plenty of cases available from large online retailers.
Make sure you always back up your contacts to your Gmail account, if you have tons of pictures, back up your phone to a cloud service, I use Dropbox, but there are other services, once you have a backup strategy and your contact are saved, if you do lots of business with your phone, you can also consider Evernote (I will do a separate post on this one).
We all need to become 100% independent from our phones, and carriers, yes some phones will catch on fire inside your pocket, but life goes on, and for less than $250 you can get an amazing Samsung J7 Dual Sim.