I haven’t been on the Queen Mary 2, but I have done the Atlantic crossing on the QE2 (considerably more than $1500 though!) twice in different eras and strongly recommend it.
It was more luxurious the second time around, but also far more… American… I’m not sure how to say this politely, especially on a US centric board, but that isn’t a good thing. A bit crass. At the time the QE2 was the largest consumer of caviar in the world, for example. Had an onboard Harrods. The chocolate was hershey’s and the food was unlimited.
Rather like a ritz-carlton hotel the 2nd time around versus the savoy the first time around.
But still worth doing, certainly. I’m sure the QM2 will be similar.