Recently I started reading "volatility trading" by Euan Sinclair. On the chapter about forecasting RV he talks about the GARCH model, but he kind of implies that its more stuff for academics, not so reliable in practice. The main criticism is that in order to define the parameters for the equation you need to do a lot of curve fitting. My question is, anyone here is using models from the ARCH family to a certain degree of success? Or should I look elsewhere without wasting too much time on things like ARCH GARCH EGARCH TGARCH OLIGARCH etc.. (ok the last one I made it up) ?