What exactly are you looking for? They are same card, thus the same speed. Many times the iBook has slightly better reception/range than the PowerBook. Its not too much of a difference though. This is due to the case and antenna, not the card.
My 15" PB has fine wifi reception.
At home, I'm one floor up through standard building materials, about 20 feet in a straight line from the AExpress. Printing via Bonjour is a snap, too.
At work, I am perhaps 50-60 feet away, though one cinderblock wall and several sheetrock walls.