Which of the lines in your official or general opinion has the most broken down trains that are still being repaired, or just need to be replaced. The obvious answer would be Hudson because they are placing the m7s on that line. But I wonder....
The placement of M7's has nothing to do about were brokendowntrains are but were technical support from Bombardier is. during first few weeks incase a breakdown would occure it would be eassier to rescue a M7 set with Harmon yard crew or MO protect engines.
The Harlem/Hudson equipment is normaly not captive to one line but circulats over both lines.
The New Haven Equipment is currently in roughest shape and held together with spit and glue.