yes, I've had it on our outback for almost 10 years. it's easy to install, uses the same wires as the usual cheap factory guage. It is consistent and repeatable even on the black tank. The ONLY time I've had it be the least bit suspect on readings is if the galley tank ends up with a bunch of soap suds after washing dishes. It may read high for 30 minutes or so.
There is one downside to the system. the scale ASSUMES a completely rectangular tank. so for your fresh water the % reading is very accurate. for black/grey tanks that have a sloped bottom or irregular shape, it will show it filling faster than it really is.
However, there is an easy solution. Ours reads in 10% incremennts. what I did is useing a flow meter on a hose, filled the black and grey tanks and at each 10% increment noted how much water (gallons) was at that level then made a "cheat sheet" I post next to the tank. So in my case, 32 gallon tanks, 50% on the meter has the tank filled to about 12 gallons IIRC. so my sheet shows 20 gallons for remaining capacity.
Ours is for 4 tanks, fresh, grey, galley, black along with switch for pump.
Measure your tank height first, then pick the guage that best fits the tank height and gives you the best resolution.
Once installed you may find like I did that 100% isn't completely full, the top of the guage must be slightly below the top of the tank. I just noted the remaining capacity in gallons with the tanks read 100%, but in the end I like that because now when a galley tank reads 100% I know I have 5 gallons capacity remaining before I run into trouble. likewise for the grey and black.
2011 Keystone Outback 295RE
2004 14' bikehauler with full living quarters
2015.5 Denali 4x4 CC/SB Duramax/Allison
2004.5 Silverado 4x4 CC/SB Duramax/Allison passed on to our Son!