(EDUCATED RESPONSE)
At the moment there's only three 100% IND lines and four 100% BMT lines . The rest are hybrids, spending time in both tunnel systems. As far as this question goes, pends what you talking about...
When it comes to speed not going to mention what used to be, some of us were around (when trains in both divisions hit 50 without too much of a problem) and some of us were not, I go by what is there now. For all the "IND is built for speed people", the fastest tube is in BMT territory (I hit 58 in a R46). But the fastest local station stop is in the IND (Fastest I entered there was 46 in a R46, I can get higher in a R160 but I have to stop at the 8-car so I don't keep power on all the way down).
Current 45+ speed recs (all within the previous 6 weeks):
58 - 60th st tube, R46 (BMT)
51 - Between 34 and W4, R68 (IND)
50 - Northern Blvd cut, R160 (IND)
49 - Entering W4, R68A (IND)
49 - Entering Newkirk, R68A (BMT) *yesterday*
47 - Entering 42nd n 8th, R32 (IND)
46 - Entering 42nd n 8th, R46 (IND)
46 - Entering 63rd Drive, R46 (IND)
In the IRT there aren't as many spots, mostly because the stations are so close together, and even the express runs are generally shorter and timed. The best I've seen in my few years as a C/R:
52 - Joralemon tube, R142
49 - Between Hunts Point and Parkchester, R142A
48 - Between GC and 59, R142
46 - Between Allerton Av and Pelham Pkwy, R142
Of course higher numbers were achieved years ago when things were faster I kinda get tired of hearing stores of slant 40s entering Newkirk at 55 and making a station stop lol.
As far as women go...
Latinas - Between 149th-GC and Mosholu Pkwy , Bedford Park and 145th , 231st - 137th , 207th - 168th , Junction Blvd - Queensboro Plaza , Woodhaven Blvd - 65th .
Blacks - Canarsie , Bway Jnct , Church Av - Flatbush Av , Parsons/Archer , Allerton Av - 241st , Gun Hill Rd - Dyre Av , Utica Av .
Eastern Europeans - Ave J - Ocean Pkwy , Bay Ridge Av - 95th, Neptune Av - Ditmas Av , Graham Av - Bedford Av .
Asians - Main St , 9Av - Bay Pkwy , 8Av - Ave U .
Take you pick, the rest of the areas have a little of everything.
Equipment...
The only IND specific train right now is the R32, the only BMT specific train at the moment is the R143, everything else (that's not IRT) is shared by both divisions. I heard a comment about IRT "boxlike" trains, and if anything the R32 is the most boxlike train in the system as it's almost as wide as it is tall.