When choosing the best compact steamer, I loot for specific functions of the steamer. One main function I want is if there is an automatic turn off after being on for a specific amount of time. I also want a steamer with multiple heat settings in case it gets too hot or too cold.
Choosing the best is all about personal preference. Find one with a long hose and a high temp of steam. The hotter the steam, the better. Battery power is usually not as good as the kind you actually plug into a wall since they have power limitations. Extra extyensions are always nice too