I agree with this. OLED would be nice, but it wouldn't be a reason to upgrade. If that's the only difference between the iPhone X and iPhone 7s, I'd go with the 7s (but there will obviously be more).
I currently have an Air 2, just ordered a Pro 10.5. With all these new features coming in iOS 11, I want to make sure I have the latest hardware to take advantage of it all. My Air 2 has served me well, it's the longest I've ever owned a single Apple device (2.5 years), but I'm starting to see slowing in UI elements. It'll get passed on to my grandmother as an upgrade from her Mini 2 (my old iPad) which she has said she wished was bigger, so that'll be a nice upgrade for her. The mini 2 will either be sold or kept as a spare then.
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I just want to address that you shouldn't feel burned. It's been 8 months since the tMBP came out, and Apple generally has an 8 month release cycle on MacBooks. The upgrade period for the 2014 and 2015 models were just elongated due to lack of new parts available. The only difference is the processor architecture: Skylake vs Kaby Lake. It's not even a full new architecture, like Haswell vs Skylake. It's an optimization like Haswell vs Broadwell. Battery improvements and slight speed increases are the most you'll see.