I opened two demo accounts: one with HotForex and the other with ThinkForex. (UPDATE: ThinkForex just lowered their spread on EURUSD to 0.2! HotForex's is 0.3 the last I checked.)
The backtests (aka Strategy Tests) I have done with optimized settings on both brokers vary a fair bit. There is another way to get 90% accurate results, but it involves getting data from a site and adding to the MT4 history, etc. I might do that yet.
EXPERIENCE thus far:
I have not had FGB installed for long and the holidays meant that the broker was not open certain days as well. However, yesterday - on a $5000 Hot Forex account with minor tweakings in the settings and with Trailingator EA also running - FGB traded successfully for a $228 profit!! Awesome. Makes me almost wish I was using real money with those results!! But this is just the first day of active trading for it.
So, one day of excellent success, no losses yet. I then changed the license to ThinkForex and am running it ACTIVE there on another $5000 Demo account. No trades today. The backtest on ThinkForex was not as profitable as on HotForex, but that is without those extra history files; so, how accurate this is, I don't know.
The reason I changed to ThinkForex immediately is because of their lower spread announcement. This is the currency that FGB recommends, so any lower spread on such currency is a benefit for us "trendy" traders.