They're not that hard to land though due to their incredible speed once fired and the Firefly also has long-range with both the Tulips and the main gun so you could snipe an enemy vehicle from the FOW without them knowing until they hear "We've lost a panzer."
They're too gimmicky. They take forever to reload and cost a ton to buy and use, but also allow the Firefly to instant nuke medium tanks. With people hating instant squad-wipes, imagine instant tank-wipes. What the Firefly needs is more reliability and less reliance on being a one-shot tank removal button that isn't that effective outside of that role.
Except they are really hard to land since the tulips have to wait for the turret traverse and the firefly has one of the slowest in the game.