As I say, I use a tick chart as a 'proxy' so am perhaps not best qualified to comment. But I will anyway.
I think one of the big difficulties (at least I found it challenging) is the sheer volume crossing the 'tape' which is pretty massive compared to the days of Humphrey Neil & 'Rollo Tape', (or Livermore for that matter) wrote about the tape. That's why a proxy works for me. I would like to master o reading the raw data but as I get older and slower I guess that's less likely. I also switched to zenfire data feed recently man that has a lot of ticks (compared to some).