Do you find yourself thinking 'I wish I had a small screen on my keyboard to tell me my CPU usage!'?
That should answer your question. I am, of course, biased, I bought a G11. However, many people prefer the older style of the G series anyway (i.e. G11 and old G15), and it has more function buttons and a matching colour. Mine looks good with all matching lights on my mouse, case and monitor, superficially speaking.
I'd say save your cash and get something else for your PC with the difference.