The original topic was Dukascopy or MB Trading.
In the case of MB Trading, you should familiarize yourself with the following ruling, which is, according to MB Trading, as I found out, not eligible for appeal.
According to MBT, it periodically happens that "the market experiences an erroneous spike in the offer quote that causes an execution of your order". Let us say this is e.g. 60 odd pips away from the true market, leading to an unintended loss, at the end of the day, of let's say 130 odd pips.
This would be, according to MBT, "unfortunate, but does periodically happen", so "it is important for each trader to monitor their trading activity and if an execution appears to be outside of the norms of the current market, it is best to call the Order Desk to check to see if the execution will stand or not. The Order Desk will always give you the most current information possible. It is possible that when you call into the Order Desk that the destination had not yet ruled on the execution(s). These types of rulings are not eligible for appeal."
Not eligible for appeal, got that ?
You would be well advised, imo, to inquire at MB Trading about examples of such occurrences, the frequency of "spikes", what exactly constitutes "clearly", who decides on what is "clear" or "not", what happens if you don't react conform their Clearly Erroneous Policy for whatever reason (illness, not being familiar with this ruling and closing such a trade yourself, etc.) and all other things that may be "clear" to MB Trading but not necessarily to you. I would do this BEFORE you become a customer, because in my experience it becomes a tad difficult to communicate with them once you are a customer, which is a bit weird for a company that has "earned Barron's Top Broker Rating" for 2010. But then again, that may be just me; you will have to judge for yourself and fill in the blanks BEFORE you do business with them (or anyone else for that matter).
I don't know about other brokers, however Dukascopy does not have such a ruling I was assured, does not experience many spikes, and apparently solves it a different, more customer friendly way, which I'm sure I will find out some day as well. Tradestation also do not have such a "Clearly Erroneous Policy".
You can find the ruling here: http://www.mbtrading.com/disclaimerCEP.aspx
Good night, and good luck