Since 1967, it's hard to really categorize a line on the B Div. like ( etc. as IND or BMT. While there still are some lines that you can do that to, IDing a line (Brighton, Fulton, etc.) as IND or BMT is the only way you can really label a line by it's former company.
I have always like the IND, it wasn't until I was in high school that I really ever used the BMT. To this day I usually don't use that BMT and I never really have a need for the IRT.