Background on Me: Been a part-time Mac user since around 1996 in elementary school, full-time since 2003 in High School. I'm a believer in the apparently old-style of using different machines for different tasks. I have Macs from the good 'ol days of B&W screens and 8MHz 68000s up to a 2016 MacBook that exemplifies everything about the New Apple, and many in between. Main machines at home are a 2010 Mac Pro, 2016 MacBook, 2012 mini, 2005 12" PowerBook. Main machines at work are a 2010 iMac, 2008 iMac, 2011 Air, 2010 MacBook, 2011 ThinkPad T420s.
Feaures-wise, here goes...
Mission Control: I was incredibly displeased when this abomination of Spaces and Exposé came out in Lion, as it took a few features from both, made them worse, ditched many features, and made using multiple monitors a pain. I do appreciate that they kept at it for the next several versions, and El Cap had the first version that I really enjoyed using again, particularly with multiple monitors. I don't really have any particular issues with it at this point, and can happily switch between Mission Control and Spaces/Exposé on my older Macs.
Spotlight: I found Spotlight in Tiger to be vaguely useful, mostly for finding things that I didn't want to search for (this was before I got obsessive in my file organization). Leopard - Mavericks got much more use from me, as it gradually got faster and expanded features. I think it was in Lion that I finally ditched Quicksilver to use Spotlight as my launcher. The current incarnation though, I use it so much. Spotlight is one of those features that, IMHO, has just gotten better and better since its introduction.
QuickLook: This is just wonderful. It's a bit painful to use anything pre-Leopard due to the lack of QuickLook.
Gestures: This rolls the trackpads, magic mice, etc. all into one point. Mother of God, Apple does still have the best trackpad experience out there. The gestures are the thing that I miss most about using my PowerBook, as they make using the machine so much more pleasant and quick. I don't have any issues using a Force Touch trackpad on my 2016 MacBook; it feels for all intents and purposes just like the standard ones on my 2010 MacBook or 2011 Air. As for scrolling, I found Natural Scrolling to be no real issue after a couple days of adjustment, and I now use it on all of my Macs. Even my PowerBook running Leopard using a little app called Scroll Reverser.
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