I scalp /intraday trade (always flat EOD) and would never use it for anything other than scalping.I only trade stocks that are very active/liquid stocks.
VWAP is the only thing I have on my charts,but I find I don't use it as much as I use to. If it meshes with my instinctive chart skills for entries and exits,that's a positive.
That being said.....
VWAP is best used during the early hours .
VWAP is less sensitive to price as the day moves along.
VWAP lag is more pronounced later in the trading day.
If a stock has a nice run up and then retreats back to VWAP ..this could indicate a strong support area and possibly another mini run .
You can't rely on the VWAP only for valid buy or sell signals,you have to have some chart skills.