172 RG manual says power out at 50' (obstacle). Don't do that. In the DA20 I'd have the power out at 1,000' AGL sometimes, and still float 2,000'. The DA42 was good with power at 15%-20% until just before flare, would give you a nice float for 300'-500' to hit your spot. I usually keep the slighest power in on the A36 until the wheels almost touch. Add all your drag factors up and It'll sink pretty predictably, just make sure you know the glide profile and keep your 110 +/- (Vg) on the way down or you'll have zero flair. The feeling of running out of elevator sucks.