A tank is the single most worthwhile compressor feature. The motor fills the tank, shuts off, and you spray from stored air: pressure stays steady (no pulsing in your line work), the motor rests instead of running hot, and the room stays quiet between refills.
Tankless compressors work, but they run constantly and telegraph every motor pulse into your spray pattern. For apartment benches, a small tank plus auto shut-off is the difference between a hobby and an argument with your neighbors.
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