I have 2 Sena 20s EVOs and my coach has a set of Sena 20s (the EVOs have a shark fin antenna, the non EVOs have a pop-up antenna). We use them winguiting, freeflying, and under canopy, with pretty good success. One time, when he was turning a load from wingsuit to freefly (not a fuel load), I managed to give him a play-by-play of the incoming plane landing and taxiing down the runway from the air (I was just entering the pattern) as he was running to change rigs and get to the loading area (we land across the street from the airport). It works much better win in-ear noise isolating earplugs (I use the Etymotic Research ER-6i. And I'm not sure what he uses. The Ryobi construction headphones my other friend used when he borrowed my spare Sena worked well for him as well. Cheapo and free in-ear headphones don't work very well, nor does using the in-helmet soeakers supplied with the kit (way too much wind noise) though they are quite loud, and work great on the plane. Just not in free fall. --- You fail at 100% of the things you don't attempt.