I'm flying a TB20 at the moment with a
JPI EDM-700 . Once calibrated they're incredibly accurate, giving fuel quantities accurate to the litre.
(The other day - showed 57 litres burned / 268 remaining. Fuel put in to re-fill tanks - 57 litres
)
That plus the engine indications that come with the unit mean real savings in fuel consumption due to more accurate leaning. I'm definitely a fan.