Thanks to all for the advice.
However if I'm turning in the S5 for credit against the S7, should I first back up the S5 using Kies or some other app? And will I then be able to restore the backup to the S7?
Yes. Just back it up using Samsung Smart Switch. That's the program that will restore everything you've backed up to your S7. I don't think Kies will work to restore to an S7.
When I get the S7 I will already have turned in the S5. So would it work if I backed up the S5 to my Galaxy Tab2 beforehand, using Smart Switch, and then transferring the data from the tablet to the S7?
Any pitfalls I should watch out for?
Once again, thanks for all the help.
As it turned out when I exchanged phones the Bell store manager moved all the data for me from the S5 to the S7, and then showed me how to reset the S5 and delete everything. Terrific service!
But as I get to know the S7 I'm sure I'll be back here with questions.