Are high compression pistons worth it?

And are they a complete pain to fit?
I was toying with the idea, if I can somehow stop the girlfriend finding out, but I'm not sure if it's worth the effort and expense.
So if any of you have fitted them, is the difference noticable, and was it worth it?
Cheers
George
I was toying with the idea, if I can somehow stop the girlfriend finding out, but I'm not sure if it's worth the effort and expense.
So if any of you have fitted them, is the difference noticable, and was it worth it?
Cheers
George