Totally - PSI and WM don't factor into what makes a kid gifted, but they sure are nice to have! My son's WM is around 128 and with his strong Verbal and Performance scores, it's sort of scary to watch him use his WM. His PSI is around 100! That's a problem, because all those amazing ideas inside just jam up at the lips.
That's about what my dd12's profile looks like as well -- high scores on VCI, PRI, and WMI and even lower than your ds' on PSI (42nd percentile which was something like 90-something). I, on the other hand, have a personal weakness in memory and am really, really fast so dd's complete lack of using a planner drives me batty but she has the most amazing memory and it hasn't tripped her up yet!
P.S. -- this is my kid who has skipped a grade and she's still a stellar student even with her speed being truly low (or at least on the lower end of "average.")
