Sitting lower after TSB rear leafs

I am noticing some serious sag after having my rear leafs replaced under the TSB this past year. I am guessing maybe 1 - 1.5" difference from before. This is on a 2008 DCSB Prerunner. If I were to install an airbag kit and inflate them to raise the truck around 1.5", would this basically make it feel like there would be no suspension in the rear at all going over bumps ? What are my options ? Are the air bags a good solution ? Aside from a load of mulch and helping people move, my truck sees very little heavy hauling and no towing.