Since I got ruin wings I haven't used any other titan exotic in pve. This nightfall I used a thunderlord exclusively, on my titan. Never ran out of ammo. People dont understand is that sometimes it may not drop all that frequently but when it does it fills almost half of your heavy ammo. For instance. Ghorn holds 7 rockets. With ruin wings picking up one heavy ammo pack on the ground gives you 3-5 rockets. Usually you only get 1 or 2 when not wearing them.