Design
The case looks slick, with a combination of matte black magnesium and aluminum elements for the base, palm rest and keyboard deck, the latter two of which are covered in this good looking and comfortable and grippy rubber-like soft-touch material. The lid on the non-touch model is also made up of matte black magnesium alloy. In my model, this is not the case. To better support the heavier touch display, yet still keep the weight worthy of the "Ultrabook" name, Dell's engineers opted for a carbon-fiber-reinforced plastic lid (you won't find any plain plastic on this machine), coated int the same soft-touch material as the keyboard deck.
As we're used from Dell's business line of notebooks, the build quality is solid: the palm rest does not depress when pressed down, nor does the lid bend in any way if twisted. Even the hinges are solid enough to not let the display assembly wobble when typing. The only time this display moves, is when tapping things on-screen, but this is to be expected - you are applying force on it with your finger.
The hinge covers are made of metal and are as robust as they look.
This laptop was made to take a beating, as it does comply with the MIL-STD-810G standard, however, it is not specified how the laptop was tested: The 810G standard is a collection of tests that can be undertaken by any company without certification. These tests include extreme temperature resistance, vibration, and shock resistance and even spill and rain resistance. To keep water from getting to any important components trough the keyboard, small channels have been built into the keyboard that guides the water to a small drainage hole on the bottom of the device.

Keyboard and Touchpad
The keyboard is great. It has been updated twice with a newer-design chocolate-table-style layout and the overall typing experience is built upon the great keyboard on the E7240. The keys still have a not-that-long-but-still-long travel distance, they don't require that much pressure to press and they are quiet, comfortable and have a nice texture. The keyboard on the Latitude E720 is one of the best if not the best keyboard I ever laid my fingers on.
The backlight is a welcome bonus, but it has been downgraded: instead of 4 brightness levels, there are now only two. Nevertheless, they still greatly improve the readability in dark environments and the fact that the Fn keys are distinguished from the others by their blue color is a nice touch.

Processor
The dual-core, hyperthreaded i5-6300U is soldered to the motherboard, so upgrading it is not made easy. On the positive side, there is no need for an upgrade, as this chip can handle most of the things a normal person would do on a laptop. Compared to the older Latitude E7240's core i5-4310U, the newer chip is about 16% faster in benchmarks. Another advantage of this newer chip is that it can achieve and maintain it's advertised turbo frequency of 2.9GHz even during multi-threaded benchmarks. In single-core benchmarks, the advertised 3.0GHz can be reached and permanently maintained. Throttling is not present in either scenario, not even when running on battery power.