All I can say is that I got rid of my 2500 because I couldn't take the rough ride anymore. I live where the roads SUCK big time. Pot holes, frost heaves, etc. So I ran out and bought this Ram simply due to the new suspension.
I would much rather have the air bags than to ruin the ride with HD springs.
My biggest complaint on the 2500 was hitting some bumps on a fast curve. The rear would just step out. Hated that.

That siad I have had the back of my Quad cab loaded with wet mulch and it really didn't drop that much. I could tell the rear was loaded though. A little wishy washy in the turns. But I never bottomed out.

I respect the original post though. Some may be using their 1500 like a 2500 and may need more heavy rear springs.