Order flow is definitely more than just the DOM, bid/ask volume footprint & whatever indicators coming from those good looking blocks. I've seen those nice selling uTube videos & none of them really touch the true stuffs behind the scene. Maybe they don't know or maybe I don't know whether they know. Even the VPIN studies were discussed in the wrong direction so who know what's the intentions are.
Someone around here said one time that the resting orders are important to order flow. I may add passive orders & aggressive orders also affect the book. DOM can only give you a snap shot but not a whole picture of buy/sell pressure from that you can get those precise entries. Precise but not fool proof.
Should you buy those order flow marketing software?
Ask yourself if you know the stuffs so good that you can make at least 5K-10K a day, would you sell your stuffs to the public and having all the problems w/ nasty customers? I wouldn't. I'd rather done trading within 2 hours and take my family to Disneyland or whatever fun for the children every day.
PS: You can't tell the intention of the big blocks whether they are pressed to sell or they are pressed to fill below unless you have a whole map of market depths to see how they release or press even more.