My experience with Gain Capital was mediocre. Their spreads were mostly in their favor when compared to other retail brokers like interactive. Their support was decent but again, I was not impressed with their spreads. I used them for about 3 months and then closed my account. Not thrilled at all.
http://www.elitetrader.com/vb/showthread.php?s=&threadid=169906&highlight=gain+capital http://www.elitetrader.com/vb/showthread.php?s=&threadid=54187&highlight=gain+capital