Next we pulled out our favorite flavor of RAM: user-serviceable.

While you can only configure your MacBook Pro with up to 8 GB of RAM from Apple, you can install up to 16 GB yourself with no issues.

This is another sigh of relief from those DIYers who want need to upgrade their RAM on an annual basis.

While the individual RAM modules here are thin (~3.15 mm), the "stacked" RAM slot is a whopping 9.15 mm thick.

When your entire device is only 18 mm thick, allocating half of that dimension to RAM slots can be too much of a sacrifice, as we have witnessed in the MacBook Air and now in the MacBook Pro with Retina display.

Don't lose hope! An individual RAM slot is only 4.27 mm thick. If the design of the logic board would feature the RAM slots side by side, we could still see user-replaceable RAM for years to come.