I visited Manhattan 3 years ago and stayed in Chelsea.
I stayed in this Four Points Sheraton, the room was clean and well appointed, no rodents or bugs. *edit* When we were there all we did was sleep in the room and to be honest there was very little of that as well, we were on the run for a 3 day weekend visiting family and seeing sites, we did not need a 5 star hotel just a nice clean one with beds to sleep on. I checked my fit app after that weekend and we walked 30 miles that weekend. LOL!!
https://goo.gl/maps/tzSzUTsS8x2PBgWNA
https://www.marriott.com/hotels/travel/nycpc-four-points-manhattan-chelsea/?scid=bb1a189a-fec3-4d19-a255-54ba596febe2&y_source=1_MTUwMjY2MC03MTUtbG9jYXRpb24uZ29vZ2xlX3d lYnNpdGVfb3ZlcnJpZGU%3D
If we walked 10 minutes west on 25th (actually we dropped down to 23rd street to avoid walking between the tenements on 25th) you hit the high line which is an old unused elevated train track that is now a park that you can walk the west side on.
If you walked 5 minutes east on 25th (safe to do) you would be at Madison Square Park where the Flat Iron building is.
If you walked towards the Google Campus to the west there is an old Nabisco Cookie factory that has been turned into a cool indoor mall with lots of restaurants and shops. We had some fantastic made to order Ramen there. I also found some local beers on draft, we sat in the common area and people watched while we ate and drank.
I liked the spot, we could walk out to everything we wanted, and a couple of different subways were nearby so we could jump on and go wherever you wanted in the city.
We were all over it from the Museum of Natural History to the Guggenheim down to the financial district, into China town and Little Italy, we walked the Brooklyn Bridge at midnight one night.
I grew up just outside the city on Long Island during a time when the city was very dangerous.
I tell you that to tell you this, in 2019 when I was there, I could feel it was different than it was in the early 2000's. It seemed to be declining quickly,
I am sure the news sensationalizes things, if I were to return (no plans to) I would be more on my toes and be more diligent and observant of my surroundings.
Try not to be the only one around and if you are get somewhere quick where there are lots of people.
Hence my changing my route walking to the high line. I noticed it was a rent control area and it seemed a little rowdy there. That was in the evening when it was still light out, I made a point to change my route 2 blocks over where I knew it was more commercial with lots of shops / restaurants / bars / people and walk there.
If you there for a week you will cover the city nicely.