As far as weight coil springs are way the hell heavier than bags, enough to offset the other weights involved. A leaf spring vehicle can come out lighter. aluminum air tank(s) can help, I got 2- 7 gal tanks @10pounds each since I'm doing a navy ship horn & other items.
Reliability is mostly properly clearancing for bags ,running lines properly & having good quality valves.
Electric compressors are noisy when running, my engine driven york will be quieter & run less at a time. Dual electric compressors are more reliable(backup) if one should quit.