iFixit has followed up on its initial teardown with some focused testing on a the new third-generation keyboard present in the 2018 MacBook Pro. How well does the silicone membrane protect the butterfly mechanism? Pretty well. iFixit showered a 2017 and 2018 MacBook Pro in dust particles and then compared the result.
As shown in the photo, the blue paint particles coat the outside of the keycaps and the edges of the membrane, but the silicon covers stop most of the particles from getting into the key mechanism — which is what causes the sticky key issues on the previous models.
However, the silicon covers have to have holes in them to allow the keycap clips to attach. Naturally, dust can and will get through these holes over time. iFixit placed some sand particles into the ‘danger zones’ of the keycaps, and confirmed the keys will break/become-unreliable when that happens, just like the second-generation butterfly keys.
The non-cocooned 2017 keyboard was “almost immediately flooded” in the particles, unsurprisingly. Clearly, the 2018 model is greatly improved in regard to reliability, but it remains to be seen just how much better it is in real-world use. Over time, you only need a couple specks of dust to get in the keycaps and the keys will get stuck. It’s just the chances of dust getting in are greatly reduced with the 2018 models.
Apple is telling customers that the new keyboard is merely designed to be quieter. In an internal documentation, it is more open about the keyboard being more reliable.
One other change with this new keyboard is a redesigned spacebar. On the second-generation butterfly keyboard, it was nearly impossible to remove the spacebar keycap without breaking it. iFixit reports that the third-generation spacebar separates easily — without permanent damage.