As a 100% mechanical trader, I found papertrading useful as a newbie. It helped my wife and I work through the logistics of keeping a log, checking fills, and developing a feel for the process. Also, just sitting and waiting through the trades and developing patience was valuable. I changed my environment until the stress was gone (eliminated the charts on the screen and put tape over the realtime P/L). Then it became very mechanical. When I switched to realtime trading the process was smooth and although my big mistake was to start a journal at the same time, it worked out fine. From a practical standpoint I found limit orders were worthless (simulation gives you a instant fill when the limit is touched...only in my dreams). Stop orders were filled accurately. Market orders were off by the spread (simulator always gave me buy fills on the bid and sell fills at the ask). As long as the method takes into account proper slippage, I think papertrading is the way to go before putting real money on the line. I've seen a few surprises since going live more than two years ago (like 4 points slippage once on a stop order in the ES), having a couple of trades broken and logging in the next morning to find a position I thought was closed. Other than that the papertrading experience was very useful and I highly recommend it to just going cold-turkey live.
42yotrader