Garmin GDL49 displays on the GNS430/530 series. NEXRAD looks blocky at low scales.

By our guessestimate, there are about 3500 datalink systems of various types in the world of small aircraft GA. That’s more market penetration than we would have expected and enough to gain informed perspective on how this datalink idea is working.

The upfront summary: owners tell us you gotta have this thing; all of the users we spoke to—15 between e-mail and phone conversations—say they love having weather data available in the cockpit, even when the system doesn’t work all that well. (That turns out to fairly often with a couple of the systems.) We interviewed or exchanged e-mail with users of all of the popular systems and found that most…