I went on the London/Paris trip last year and it WAS excellent! I wrote a trip report somewhere on another forum (this one wasn't available then). Yes, it is worth the $$$$$$. Personally, I LIKE larger American style rooms, conveniently located and they met the mark in that category most definitely!
Can you do it cheaper? Sure, but this is where you get what you pay for. Granted Big Ben and Notre Dame don't change, but the WAY you get to see them most surely does - and that is what makes this worth the bucks.