Build Quality
Overall build quality is very solid. When shaking the mouse, a very minor rattle comes from the main buttons. When applying lateral pressure, no creaking or flexing of the shell can be observed. Activating the side buttons by squeezing the sides is impossible. Lastly, accidental clicks when slamming down the mouse do not occur.
Main buttons on the DeathAdder V3 Hyperspeed are very good. Both pre and post-travel are low, resulting in a firm and snappy button response. Despite being visually separated from the shell, button movement is low even when provoked. Button stiffness is medium. A pair of Razer-branded 3rd-generation optical switches are used.
Side buttons are very good. Both pre and post-travel are low, though much like on the Viper V3 Pro, button response is somewhat unsatisfying, as feedback is lacking on the back button in particular. The actuation point is even across the entirety of these. Button placement is good as actuation is possible very easily by rolling one's thumb across. A set of surface-mounted switches (beige plunger) from CF (ChangFeng) are used for these.
Underneath the mouse is a single button which either cycles through the set CPI levels if pressed briefly or turns the mouse on or off if pressed and held, which works well. A seemingly unbranded tactile switch is used for this one.
The scroll wheel is good to very good. Noise levels are elevated, but tactility is great, with clearly defined steps allowing for controlled scrolling. The encoder comes from TTC (blue, white core) and has a height of 8 mm. The middle (scroll wheel) click requires high force for actuation. A seemingly unbranded tactile switch is used for this one.
Surface
The DeathAdder V3 Hyperspeed has a matte surface all over. Grip is fine, and it doesn't attract fingerprints or dirt too much. It is easy to clean, and there are no signs of wear left after doing so. All in all, excellent materials.
Disassembly
Disassembling the DeathAdder V3 Hyperspeed is easy. The Torx T5 screws are found beneath the front and rear skates. After removing those, four additional clips at the sides need to be dislodged, doing which may require wedging a credit card (or similar) in between. When separating top and bottom shell, make sure not the rip the cable connecting the two.
The internal design is uncommon yet highly efficient. A plastic assembly is screwed into the top shell (using no less than nine screws), which holds the side-button PCB along with a PCB holding the main button switches and scroll wheel, both of which are connected through an FFC to the main PCB. The main PCB is very compact and thin, and three screws are used to affix it to the bottom shell. Of particular note is the antenna construction, along with the external illumination for the sensor. The MCU is a Nordic nRF52840, whose datasheet can be found
here. The Bluetooth capability of the chip remains unused.
As for the soldering and general quality of the PCB, I'm unable to find any noteworthy flaws.