A monitor arm is one of the highest-leverage WFH upgrades you can make, but the buying decision is mostly about load capacity, not features. The single biggest mistake buyers make is picking an arm by maximum monitor diagonal. Diagonal tells you almost nothing - a 32-inch ultrawide can weigh 17 to 22 pounds, while a 32-inch 4K flat panel often weighs 9 to 12 pounds. The arm has to support the actual weight, not the screen size, and most cheap arms collapse or sag the moment they exceed their gas-spring rating. Read the monitor's spec sheet for weight, then buy an arm whose middle of the supported range covers it. Arms running near their max rating drift downward over months as the gas spring weakens. The next decision is single vs dual vs ultrawide. Single arms (Ergotron LX, Humanscale M2.1, Herman Miller Flo) are the right call for most people running one main display, and they are dramatically more rigid than dual arms because there is no shared center post amplifying micro-vibration. Dual arms make sense only when both monitors are similar weight and size - mixing a heavy 32-inch ultrawide with a light 24-inch on the same dual arm creates uneven load that no center post handles well. For ultrawide owners running 34-inch curved or 38-inch panels, you need a dedicated heavy-duty single arm rated for 20-plus pounds (Ergotron HX, Humanscale M8.1, Jarvis heavy-duty). VESA mount compatibility is rarely a problem - 75x75mm and 100x100mm are the universal standards and almost every modern monitor supports one or the other. The exception is some thin LG and Samsung consumer panels that ship without VESA threads on the back, which require a no-drill adapter plate. Mounting hardware matters more than people expect. C-clamps work on desks 0.4 to 2.4 inches thick with a flat underside, which covers most desks but rules out rounded-edge IKEA tops and very thick solid-wood slabs. Grommet mounts need a 0.4 to 0.6 inch hole through the desk surface, which most pre-built standing desks include but many fixed desks do not. Skip arms with painted-on cable management - Velcro straps and the channel down the back of premium arms (Ergotron, Humanscale) keep the cable run clean for years; injection-molded plastic clips on cheap arms snap inside six months. The other place premium arms earn their price is the gas spring itself. Premium gas-spring arms (Humanscale M-series, Herman Miller Flo) hold position indefinitely once tensioned correctly. Cheap arms drift slightly within weeks. If you reposition your monitor more than twice a week - for screen sharing, for posture changes, for pulling the screen forward to read fine print - buy premium and skip the upgrade cycle.
