Good to hear another positive report - planning on adding them to my F250 as well.
Seems like most who have had both air bags and the Timbrens lean towards the latter. Timbrens are cheaper, easier to install, far simpler, nothing to break, nothing to adjust.
And lastly, the main reason they appeal to me - the ride in my '97 F250 is quite harsh when unloaded. Adding air bags would make that worse. Timbrens have no impact on unloaded ride.