Full Series All Hail the Hailfire Droid

Totally! That scene on Bal'Demnic was AWESOME! How they just stepped over the resistance.
But with the introduction of the Droid Gunships in S5, I am sure that Hailfire droids and Homing Spider droids are not far behind.
I think they are being saved so these droids could provide a special flavor to a battle.

The same way the Tri-droids were only used so far for Christophsis or the Super-tanks were only used on Geonosis or like how the Crab droids were essential to the Citadel arc.
The same way these two types of droids will appear...