Great work.
Rex often turns the perspective by just a few degrees and cranks up contrast, and he often arrives at scenes that appear a good deal more three-dimensional to me than some of the original TSoMI one point perspective "bullseye" setups. Of course the ReMI art team could leave no formerly straight line alone, things slope, lean, bend, dangle, and compress, and you can almost hear that woodwork creaking in some of the backgrounds. The former rich blue is no more, Rex likes his cyan and tinges of green, but then again, these deep blues were kind of a catch-all default color on Melee Island anyway.
As to mere subjective, personal taste, I don't care that much for the new Scumm bar or the governor's mansion interior, but the lookout, the prison and the giant monkey head I find even better than the original. There, I said it.
The ReMI backgrounds always contain pretty much exactly what was in their 'original' counterparts. But there's always a twist and a twirl that seems to playfully pull away nostalgic recognition just out of reach.
I hope that Monkey Island fans will eventually universally be able to find that nostalgia grappling hook in the inventory of their own minds, and draw themselves, by their own strength, back into childhood memory at first, and later, into the grand new adventure of their lives.