Unlike most of its competitors, the GDL 39 also offers ADS-B traffic. Now, there are two schools of thought on ADS-B traffic. Bear in mind that it is an incomplete
solution. Unlike with an installed active traffic system, with ADS-B you only get that traffic that passes through the ADS-B system, either through an airplane that's participating or a ground station that gets relayed through that ground station. So there's a lot of traffic it doesn't see. Part of that is the fault of the FAA, which has decided not to send traffic to non-participating ADS-B customers, a decision that's impossible to defend given the safety ramifications of not getting traffic info to as many people as possible. The FAA is dead wrong on this one. Then again, with ADS-B traffic via the GDL 39 and shown on the iPad, you do get some traffic, essentially for free, which is more than the complete lack of traffic that most pilots get today. Furthermore, as more and more airplanes equip with ADS-B, there will be more and more traffic available. Eventually, everybody will be broadcasting.