Nope, you're one of two. I do 400 administration. I actually prefer it to the windows systems in our data centers. The way the OS meshes with the hardware is 2nd to none.
In a previous life, I did AS/400 consultation. I don't miss it a bit. It is still an amazing OS. The POWER Architecture is still absolutely amazing and years ahead of its time. I loved explaining to Windows and *ix guys that I could shut down everything or anything on the machine down and watch their jaws hit the floor.
Virtualization 30 years before popular adoption was awesome... SNADS, twinax, Paged Memory Disks and ALL SYSTEM Saves were not.
I'm waxing nostalgic... I never thought I'd do that.
I still hate JDEdwards though.. what trash.