I tried the Fliegerfaust several hours each night, and this is what I found on performance.
1. You definitely need a reliable resupply for the Fliegerfaust. If there are lot of aircraft flying around, your supply will be gone in a heart beat.
2. The enemy is already catching on that fly around your aircraft resupply point near your spawn is risky now. You will see more enemy pilots resupply on their side of the map.
3. Lately the enemy is flying at high altitudes and taking a quick dive bomb run, but now they climb out and do not hang around at low altitudes as before.
4. From two nights on several winter maps with fixed AA, the new weapon has practical eliminated the outrageous pilot scores 40+/0 kills from the past. (Nice work DICE
, I bet you have not heard that for awhile).
5. You are easily killed if you are close to the enemy on the ground. When you fire the Fliegerfaust in the air (looks like streaks of lightning), all can see where you are (much more than rifle fire). You find yourself looking in the air while the enemy moves in on you.
6. The Fliegerfaust is an excellent AA weapon, but don't expect a lot of points using it during the whole game. The best k/d for me using it during the whole game was 14/1. But after the results of the game, I placed on the bottom third for points.
7. A lot of the quick kill video using the Fliegerfaust where taken on the first days when the weapon came out. Don't expect it is that easy now, pilots know about the new weapon now.