I have been using P & F charts for years. I rely on them to detect trend changes - S/R levels. Box size is all important and can change over a period of time. I have tweaked my charts by entering dates in the actual boxes which give me an indication of the strength of a move. I don't put too much faith in price targets and rarely use them for that purpose.
I originally hand drew them - it gives you a real feel for price action, as you said. Now, I manually update them on a spreadsheet. They give you a pretty accurate picture of price movement and areas of strength, or weakness.
I don't know of anyone else that uses P & F charting.
Just another tool in the box.