Planing depth
The greatest thickness of the layer of material that the planer can remove in one pass (most often the design provides for depth adjustment). The larger this parameter, the more performant the tool will be and the better it will be suitable for large-scale work. On the other hand, in fact it is rarely necessary to remove a large amount of material at a time, and tools capable of this require powerful (and therefore expensive) motors. Therefore, in most consumer-level models, the planing depth does not exceed 2 mm; more "deeper" units, usually, belong to the professional class.
Noise level
The maximum noise level produced by the planer during operation. The lower this indicator, the more comfortable the use of the tool, the less inconvenience it creates for both the user and others. Note that the noise level is measured in decibels, and this is not a linear unit — in other words, sounds with a difference of several dB in volume can differ significantly. A few examples for comparison: 75 dB noise is approximately equivalent to a scream, 80 dB is a motorcycle engine, 85 dB is a loud scream, 90 dB is the sound of a freight car moving at a distance of 5-6 m, 95 dB is the noise inside a subway car.
Power cord length
The length of the network cable can tell you how far from the outlet you can operate the device. Therefore, for domestic use, it is more relevant to choose models with a short cord, for construction work or use in production, in the garage a longer cable is better.