Just my 2 ct... as for
smart hardware-upgrading
Modern Processors have for us normal Users a workload of only about some 10-20 percent, so the "power" of the processor is NOT a benchmark for upgrade.
BUT: RAM and SSD are a fantastic tuning and will making feel like with a new mac!
PLUS: "OLD" Macs before 2013 are fully upgradable for little money.
PLUS: If you have to repair an "OLD" mac, you will be still capable to do it because NOTHING IS SOLDERED AND GLUED in it and you will find easily used parts in good condition.
we run some "old" MacBook pros in our family:
MBP 2009 (unibody)
MBP 2011
MBP 2012
and a
MacPro 4,1 from 2008
upgraded to ElCapitan on the 2009 (4GB RAM, still a 2TB HD)
and the 2012 MBP (16GB RAM, SSD)
The others will be upgraded soon.
The 2009 runs
faster than before, even with the HD, although still with a classic HD - soon upgrading to a SSD.
"Old" Macs have lots of advantages in comparison to the soldered/glued "new" ones produced after 2012:
look in this thread, it is worth reading all 11 pages:
https://forums.macrumors.com/threads/why-are-newer-macbook-pros-not-upgradeable.1960895/
So - as long as you don´t play games or big scientific calculations on the MB, but use the Internet, office apps, load your camera pictures (can always be done with a SD-Adapter on an old Mac) , yes even if you do (not too complex) Photoshop, even if you hear/store music on your mac, the "old" ones will be fine.
Prices for top-SSD and top-RAM are really ridiculous low now - especially for the "OLD" Macs.
As for Sierra: I still stay with the last OS before the actual one rolled out.
This is at the moment OS X 10.11.6
If you want to send easily photos fri
om fout iPhone to jout Mac, you have lots of possibilities.
One is just to send selected ones from your smartphone by email to yourself - there it is on the Mac, if you open your email...
As for transfer from your camera: There are USB-SD-Adapters for 10 USD, there is bluetooth, ....