I haven't used it before, but..... the oldest a/c in this game world, perhaps is:http://www.airwaysim.com/game/Aircraft/Used/View/72837/?manufacturer=McDonnell+Douglas&range=0&capacity=0&style=1
and from the global statistic, there are still 38 DC-9 in service, with an average age of 27 yrs old. And SOUTO still uses DC-9 which contributes about 6% to their total a/c.
From the spec, the a/c is really nice, though the fuel consumption is a bit higher (when compared to similar size a/c e.g. E195). But don't forget it's a 70s design, a 40-years old design! When compare to those newly made Russian-made metal (e.g. T204), it is still preferable!
Really want to buy two to three DC-9, just for fun! I just want to hear from those DC-9 users about the comment of this classic a/c.