I've got an iMac from late 2007 with 4GB of RAM and and an SSD, and also a MacBook Air from mid 2012. They both work like a charm. My iMac has had some minor repairs, but my MacBook Air hasn't given me any trouble yet!My MacBook Pro from Late 2012 still runs like on its first day.
My first gen Apple Watch on the other hand was dead on arrival (so slow, Steve Jobs would have never allowed it)
Oh, and a 2006 iPod, perfectly functional! Still using it as my main MP3 player.