My sensors do not use long range as I mistakenly said. They are G5 lightweight of course. My Python, Krait and FDL use long range Ds. And usually just G1 or G2 to get a little extra. Typical emission range as shown on Coriolis is about 60% of what I'd call effective range. My Courier's sensors are shown as 4.6 km, but hold scans to 8 km, with a few cooler ships maybe dropping before that.
As I see it, A sensors are really good for two things. They are better at resolving those cool ships. And they are very useful when you want to target specific ships, such as power play, massacre missions or if you are being highly selective while bounty hunting. For me though 8 km is more than enough, especially in the typical places I fight, RES sites and CZs. There are always a bunch of ships well within range. For my ships I'd rather trade that range for lower power, heat and mass.