I bought AirLift 5000 with internal jounce, the internal jounce pad was major consideration then price. In my application it was required that I remove the jounce pad to install airbags, so I installed the internal jounce airbags. Which is useless unless you are taking out your jounce pads for your installation. I dont know if Firestone has the feature or not. But in my opinion all things being equal, it comes to price, and brand identification, and what you feel comfortable with. 15 to 25 lbs is all it takes to level me up and 10 lbs unloaded smooth out my TV when not towing. Air bag manufacturers recommend some positive pressure in the airbag at all times to prevent damage to the airbag, so you will always have 5 to 10 lbs. You will be surprised.