I posed this response to the System i Network forums when they asked the question: "If IBM came to visit tomorrow and granted you one wish, what would you ask for?"
My response sums up my only gripe with the platform:
Call the operating system OS/400 again. "i" is a broad term that confuses the hell out of people.
Some Guy: "What are you running under the hood of that thing?"
Long, awkward pause.
Bemused Guy: "O...K..."
Me: "OS/400...it's essentially a modern AS/400 running OS/400 V7R1 but they call it a Power System running i, or IBM i, or i5/OS...it's interchangeable even though they brought in the i5/OS name with the Power 5 processor and they've moved to Power 6 and 7 now but never changed the OS name to go along with the new processors. You'll find references to i5/OS on the system but it's really i now. Most of the licensed programs and literature and menus don't reference i5/OS anymore but some do. And it's not V7R1 anymore...it's 7.1"
Confused Guy Moving On: "Well, how fast are the processors?"
Me: "Well...it's a model 720, not to be confused with the old AS/400 model 720 from 1999...remember it's a Power System. Anyway it's a 720 so it's got a 6 core 3.0 GHz, but i processor performance is really measured in CPW, not necessarily clock speed..."
Mildly Frustrated Guy with the Million Dollar Question: "What's CPW?"