I have the G15 and think personally that is a great keyboard ( i previously had the G11 but umm killed it with pepsi ;p )
nice lcd screens which work with a lot of games to show stats kill/death etc. backlit and with enough programmable keys to work with. +usb ports
iam tempted to get the g19, but i might wait for the next version as the difference between the g15 and g19 isnt worth it for me.
all 3 of the keyboards are good so i dont think it would be a mistake,although you will have to decide if the features are worth it compared with the one you got (which looks similiar in basic functionality- prog.keys etc). i do love the lcd screens on mine tho

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