There is a huge thread on champagne where the bubbleheads here hang out, with lots of notes and well-informed discussion.
I am far from expert in this area - I drink a lot of fizz, but at a somewhat lower price point (~US$30-$70) so I can’t offer much. But I would say that Jacquesson (I assume you mean the 7xx numbered series) are a mile away from Krug or Dom!