It's a common misconception that its the "2nd cam" kicking in. The VVT system doesnt actually change the cam profile, it changes the timing. It isnt as sophisticated as the Honda system. Also, it doesnt advance the timing at 5000rpm, it's something silly like 1500rpm. I think it's basically to do with idle emissions.
The 5k kick is actually where the engine reaches its breathing sweet spot, so it's purely to do with gas flow efficiency rather than any mechanical intervention. This is how I remember it being explained by one of the tech boffins on here anyway
Either way, it is very nice, but not quite Honda i-VTEC nice :evil: