i just read the tape for whatever stock i'm trading. i look also at the 5 minute chart for key levels and the futures.
On our REdiPlus platform, we can choose to have the "last trade size" (with price of course) reflect either "consolidated" or "NYSE" only. We have pretty good "Price Ticker" which you can set to show all market centers, or simply click one market center to filter for only those trades (NYSE only for example). I use the quote window, with running tape, along with 2 montages, one with level 2 and one with NYOB for depth of book. I can't trade without all three being open (old timer I guess, LOL). Don