I have a G15 keyboard and I like it a lot. I have not set up the macro keys yet, though I have tons of ideas for them and
know that you can do some pretty cool stuff. The really helpful thing is the LCD screen which displays in game information such as; when you receive a whisper and from who, When your que pops up for battleground and how long you have left to join, and much more. It displays all this information even if you have World of Warcraft minimized. The other cool thing is that there are many other programs and games that are supported and people even create their own. Ventrilo is supported on the G15.
To make a long story longer. I would say that if you were to get the G15 and then get a gaming keypad such as Nostromo N52, you will have the perfect set up. That's what I have.
Hope this helps.