Genesis once bubbled...
The economics only work for people who dive a lot (putting in their own station), but for those people it works HANDSOMELY.
Not only that, but if you dive, come home, and want to dive first thing in the morning you can - without a hassle. That's flatly IMPOSSIBLE in most places (cave country perhaps excepted)
Finally, you get away from the dive-shop weenie factor. $40 to O2-clean EACH tank and valve? Huh? Take it apart, clean it yourself, log it, and that's that. For $5 worth of Simple Green and a couple of hours of your time you can do FIVE tanks. Ok, ok, the O-rings in the valves might cost you another couple of bucks. Replace the seats? Only if they need it.