It's not so much the kind of signals as it is the distance from the source of the signals. When I sit in front of a WiFi-enabled MBP, I get throbbing in my temples and headaches. If I keep the WiFi off, no symptoms. I get the same symptoms if I sit close to a router, especially one with 5G enabled. So I keep my distance from those, too.
But, yea, I am happy with it. I paid about $1,000 cdn for the 2012, 13-inch (I can max out the RAM up to 32GB, but don't quite need it right now). The 2015 only had 128GB SSD. I think my next laptop will be a Hackintosh...unless PC laptops haven't caught up with the Retina displays by then (maybe they have already caught up, I have no idea about PCs these days). 😉
Pretty sure a 2012 13" maxes out at 16 GB RAM (and I'm pretty sure that's the case all the way through 2018 13" models to this day), and at a slower clock speed than whatever RAM your 2015 had, so that's a loss there. I mean I guess if you are coming from a 2015 13" model with 8 GB RAM, then maybe you got 8 GB more RAM but at a slower clock speed, so probably a wash anyway.
The SSDs in the 2015 and newer are insanely fast, so you'll probably barely be on par there after spending more money to upgrade. Plus, the 2015s have upgradeable drives anyway.
Other than those two things, you can't upgrade a 2012 anyway. And it's that much older and closer to end of life and end of support, not to mention you gave up retina. And being bought from Best Buy, it was refurbished by a 3rd party with questionable parts.
Seems like this was a real step backwards in almost every way. You bought an older computer that on its best day, maxed out, is still a lesser machine than a 2015. Also, $1000 CDN seems insane for a 7 year old 15" machine, let alone a 13".
I just don't see the logic in this any way whatsoever,
especially at the price you paid. With all due respect, I think you got straight up ripped off by Best Buy. I'd be returning that immediately if possible and reevaluate what you're really trying to accomplish because buying an older machine in hopes of upgrading it beyond the three year newer machine you had isn't even possible, realistically.