I've refrained from posting, but feel some details, points, and misconceptions should be addressed here:
A double-drawer F&P DishDrawer has one power cord, one water supply connection, and two drain hoses which connect together to one point on the household plumbing via an included Y-adapter. Multiple single-drawer installations would involve separate power cords and water lines for each.
Double-drawer units cannot be physically split into two. Likewise, single-drawer units are manufactured as singles (there is no included bottom storage cabinet, it would be part of the homeowner's cabinetry design), and cannot be physically combined into a unitary two-drawer unit.
It doesn't happen often, but I have run different cycles simultaneously on the two drawers.
In regards to a water heat "option" ... all cycles (except Rinse-only) always heat the main wash and final rinse to specific target temps. The Eco option cuts one water change and reduces the target temps, but heating still runs as needed. The 1st-generation KA models (rebadged F&P) were reversed - normal programming was in Eco mode, with "Hi-Temp" as an option. F&P units can be run on a cold water connection, water heating is thermistor-controlled, not limited by time. Whirlpool-made drawer units of the Maytag design (Kenmore Elite, current KA models, & Maytag) may be time-limited and require a hot water connection.
As reported in a post two years ago, using a Kill-a-Watt meter I clocked my unit (on a cold fill, so it had to fully heat the water) as using 0.68 KWH on Heavy (132 mins, 150°F wash, 163°F rinse) and 0.4 KWH on Normal Eco (88 mins, 125°F wash and rinse). Both drawers running those cycles would total 1.36 KWH or 0.8 KWH.
I've posted pictures of typical loads with more items in one drawer than I've seen others have in one rack of a standard dishwasher. Two MegaRacks can be placed in one drawer, doubling the effective capacity for glasses. I've gotten 35 glasses/mugs of various sizes in one drawer. Likewise, two plate racks and silverware baskets can also be placed in one drawer, or the inserts and basket can be removed for a wide-open space. The new F&P Tall models have fold-down tines and height-adjustable side shelves.
I've cleaned the filters ~three times in six years. I've not thus far had need to take a plunger to it ... but neither do I use it as a garbage disposer. I scrape, but I don't prerinse.
Like any appliance, drawer dishwashers don't fit everyone's needs. However, a blanket condemnation is likewise unreasonable, as they do work very nicely when "the shoe fits." They must not be too bad or F&P couldn't have kept them on the market for 12+ years.