is the h/k logic7 surround sound system any good? has anyone had experience with it?

it's good as far as factory option go

big picture it's mediocre compared to aftermarket options

Where do you get your information? HKL7's are awesome and better than most aftermarket setups...
They use component and imaging, if you've ever heard one youd understand.

Obviously nothing next to Hertz or something but compared to alpine or kicker its way better.

It sounded like you were disagreeing....then you agreed at the end that it's nothing compared to an aftermarket brand like hertz.

anything Harmon Kardon has pretty awesome sound quality