Many sites have focused on what was an aside in iFix's teardown: that the label on the back of the iMac said, "Designed by Apple in California, Assembled in USA." There's plenty of speculation on whether Apple has returned to manufacture machines the U.S. and built a factory; or if the unit is custom-built or a standard model; or whether it was manufactured or refurbished; or speculation on an unknown Mexican maquiladora making Macs.
None of the stories focus on the new iMac hardware and implications for purchasing and repair. The model was the base unit of the new series.
Firstly, the new model's screen is held in place with adhesive rather than magnets. This will make the the machine very difficult to repair and certainly beyond the usual DIY job. While the RAM, hard drive, and CPU are upgradable, the work involved is considerable.
If you're buying this machine, make sure to get everything you might want preconfigured. People who might have upgraded a base iMac will have to take almost everything apart to get to the usual suspects.
Looking at the logic board, the iFixit article points to a hole passing through the board and a set of traces. These are for theoption.
We purchased the "bargain-basement" version of the iMac. We're assuming that the more-expensive version—one that has the built-to-order Fusion drive option—has this connector soldered onto the board, and a 128GB SSD placed into said connector.
In addition, the iMac's hard drive is interesting. Apple moved to a 2.5-inch laptop drive instead of the 3.5-inch drive used in previous iMacs. The unit in the iFixit article was a 1TB drive.
A rubbery housing is lightly adhered to the edges of the hard drive beneath the upper and lower hard plastic bezels.
This design is far different from what we've seen before. Since the internal components are more tightly packed than before, small vibrations may carry through more components. The rubber housing dampens the vibrations from the spinning hard drive so they are not perpetuated throughout the device.
This assertion sounds like speculation to me, but it could be right. There is a concern that hard drive micro-vibrations hit performance in server drives, which was mitigated by installing a special isolation technology in the racks and mounts. However, the study looked at numbers of drives vibrating in a rack. Could these micro-vibrations effect a single drive?
Perhaps the rubber housing is related to focusing airflow in the newly-designed enclosure. The article says the model has a single, larger fan, down from 3 smaller fans in the previous design. The rubber covered the sides of the drive, leaving open the wider side with the drive's electronics.
Check out the iFixit article. It's terrific as usual.