Getting stopped out of xone cost me 6k in lost profits. I missed 1000 shares of IRBT at 10/share in 2008 over a limit order of 10 and it never went below 10.01 that day. I don't use limit orders any more. I either use market orders or Stop loss orders. I need more time to see if I save more from losses or lose more in lost profits to make a final decision on how effective my Stop/loss strategy is.
ssys bought makerbot and I'm buying that soon I think.
Disclosure: I am long IRBT.