Dali Helicon 800. What components match with it?

An audiophile I met invited me over to hear his system. He recently bought Helicon 800 speakers. He had considered the Helicon 400 that Absolute Sound raved about, but in comparing the two, he said the 800 won, hands down.

I thought they sounded great in every way. Great bass, clarity, imaging, with a natural sound. The combination of a soft dome tweeter crossed high to a ribbon gives an open, airy quality. Plus the woodworking and finish are stunning. If you get a chance to see one in person, do so, as photos don't do them total justice.

He did find though that the Dali's made him hear that his amp was too bright, so he changed amps from an older Parasound to an Audio Research transistor. He also made cabling changes that he said made a tremendous difference.

Anyone had experience with this speaker? Does it require careful matching of associated equipment? How does it compare to the Helicon 400?