I Googled & read through many user reviews about the following Forex brokers;

FxPro: Scam (Partial)

Brief explanation: Long term users complained that after using their trading platforms for (after) a 3-6 months period; the spread becomes manipulated by the broker (to become increasingly higher & higher) to make it harder for that long-term user to win trades anymore... Claimed to be not having True-ECN spreads as claimed by the broker (but manipulated spreads)...
IC Markets: Scam (potentially)

Brief explanation: Same problem as the above (FxPro), plus another issue; that some users experienced difficulty in withdrawing their profits or even getting paid back their capitals at all... Additionally, there were also user frustrations about suspicious bugs/technical glitches they experienced in the platforms that caused them to lose profits & even their capital (& they had problems in getting back any refunds)... Claimed to be not having True-ECN spreads as claimed by the broker (but manipulated spreads)...
Pepperstone: Scam (highly likely)

Brief explanation: Suspicious company that claims to be big with established superior technology, but it could in fact be just a lie; some users claimed that this company had used random photos of large governmental buildings & had superimposed their company's logo onto the facade of the building to claim it as their very-big/established company; it is also suspected that this company doesn't actually have any of those superior technologies that they are claiming to have... Last but not least, users were facing issues in withdrawals, plus experiencing the same problems as the above (FxPro & IC Markets) as well... Claimed by users to not have True-ECN spreads (but manipulated spreads)...
DUKASCOPY: Genuine & real but with some bad points

Brief explanation: Users are generally happy & satisfied, but with some complains about the trading platform being slow & kinda primitive (aka. low-tech)... In addition, users also did comment about the somewhat bureaucratic nature of opening an account (eg. some users' application were rejected, & some were facing extends of delays of the approval process; with requirements to produce more documents)... The broker is said to accept bank-wire transfers only (which may incur some cost % for each transaction amount)... A minimum of USD$5000 is required for opening a small (the smallest) Forex account with this broker...
Source: Based on Google-Search for user reviews of the brokers listed.

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