Dyson measures the suction power of its vacuums in constant air watts. The DC25 has a suction power of 220 air watts while the DC28 has a suction power of 245 air watts.
The Dyson DC25 features the "Ball" technology, providing for easy maneuverability. The DC28 has a fixed wheel more typical of standard upright vacuums.
The carrying capacity of the collection bin is a significant difference between these vacuums. The DC25 has a capacity of 0.31 gallons while the DC28 has a capacity of .61 gallons.
Included with the purchase of a DC25 are a combination accessory tool, a stair tool and a mini turbine head (with the Animal model only). The DC28 includes the combination accessory tool, a stair tool, a mini turbine head and a "flat out" head useful for cleaning under low furniture.
Both vacuums measure very closely in their dimensions, with the DC25 being narrower by a little more than an inch. The DC25 measures 42.4 inches high, 12.2 inches wide and 14.5 inches deep. The DC28 measures 42.1 inches high, 13.5 inches wide and 14.3 inches deep.
The DC25 is considerably lighter than the DC28, weighing in at 16.12 pounds while the DC28 weighs 20.61 pounds.
The DC25 has a maximum reach of 40.3 ft., which takes into consideration the 24.6 ft. cord length as well as the telescoping wand. The DC28 has a maximum reach of 52.2 ft. with a 35.2 ft. cord length.
As of summer 2011, the suggested retail price of the DC25 Multi Floor is $500. The DC25 Animal retails for $550 and the DC28 retails for $600.