The way I see it, if the factory option was available, I probably would have done it. I really just didn't want to wait anymore. The added functionality is that I can use my on board air for air tools and filling tires. You can add on-board air for $350, or find a way to tap the air tank in the Ram OEM system for a few bucks. The big promise on the OEM air is the ride. Coming from my '05 3500 I expected a harsh ride in the '14 3500. That is not the case. The ride is still truck like, but very smooth. The advantage to the OEM system is that it will automatically air the bags to compensate for load. I don't know if there will be a user over ride to the height setting, though.
I don't know that the firestone system is an apples to apple comparison. $800 gets you all the parts (tank, compressor, bags, fittings, etc) but that was a self install. If you pay to have it done add $500. Now you are really close to the OEM price, with the addition of warranty. This is a long way of saying that I'd probably order the OEM air, and find a way to tap it for an air chuck. However, I have no complaints about the aftermarket system.
Thanks for the additional info, Alex00. If the firestone product offers a little more functionality for less cost, are there any benefits that the factory option might offer to make it worthy of comparison? Or do you think I'd be better off with the firestone option? In the next few weeks I hope to place an order for 3500 DRW Diesel and I'm shopping for trailers in the same weight and size class as the Cyclone 4000. Congratulations on your purchases, by the way! If you're picking up your trailer this Sunday, I'm sure this weekend can't get here quick enough! Good luck!