I am using both g15v2 & G510

g15
- two USB port
- no speaker & mike output
- media key need to press hard (not user friendly) and also nit back lit
- volume control very finicky
- back lighting fixed to amber color

g510
- no usb port
- built in speaker & mike output
- improved media key (soft touch & user friendly)
- improved volume control (using the scroll knob type)
- customized programmable multi color back light
- extra micro key
- better built and functionality but cheaper than g15
- looks cool when installed with win amp visual equaliser bar display plug - in + installing script to make the back lit key color changes synchronising with the music playing in win amp

I recommend u buy G510 instead of g15..better value for money

could it be they test that with the g15 v1? coz now is v2...

anyways i think i m getting g510 already