The more annoying change (imho) is how hard it's become to replace the keyboard. That used to be really easy, remove a handful of screws, slide out the keyboard, and unplug the connector. Now it requires disassembling the entire machine, at least for the X series.
The X200 weighed 1.34 kg, the X280 weighs 1.27 kg. What a massive weight reduction indeed. Totally worth ditching all upgrading possibilities.
Reminds me of Apple ditching the 3.5 mm jack with the pretence of making devices thinner and lighter, when neither happened.
From a consumer point of view, they're great machines. But from the seller's point of view, I can see why they want them to be harder to repair. I probably won't be upgrading for another few years, why should I? The whole trend of planned obsolescence is becoming more and more obvious. I hate it, but it was the obvious outcome.