My experience with Gain was for about 3 months and I was not happy at all. Their spreads were in their favor pretty much all the time. I had another account at interactive and when I compared the two, Gain didn't even come close. I closed my account after 3 months.
http://www.elitetrader.com/vb/showthread.php?s=&threadid=169906&highlight=gain+capital http://www.elitetrader.com/vb/showthread.php?s=&threadid=217156