The sewers I'm sort of mixed on. Visually it's better, but the gameplay in that section is some of my least favorite in the entire game. I think the main shaft is good (especially the elevator shot at the end) and the new locations are nice, but overall it feels gutted and much more linear. Comparatively, I think the RPD is actually a huge improvement over the original design. I just wish all of the details weren't totally obscured by the spooky ooky shadows.
To be honest, the 2 remake feels very jarring in a lot of areas and I think it's because of how jenk the development was. Starting out as a REmake-styled adaptation with Darkside assets, followed by a total reimagining, then meeting somewhere in the middle with a mix of 1.5, 3, CODE:Veronica, Outbreak, and 4. You can tell more in certain areas than others that there wasn't a clear vision of what was going on.