I trailed him yesterday in one of my instructor's horse's hacks, something like this: http://www.nrsworld.com/istar.asp?a=6&id=BIT937L!REI
I'm leaning towards that sort of hack now, since he seems to like it a lot and it has gentler pressure on his nose. If he continues to do well, I will probably buy an all leather curb.
He did fantastic in it, responded well, and stopped better than in the bit. He also backed up easy for me, something he's been fighting me in the bit. He is very light, and I ride light- he will respond 80% of the time to single finger pressure on the reins.
I'm only thinking of moving to hack after he's had two months of ground training with my instructor about giving to pressures. I could probably ride him in a halter and lead ropes, he's done so well. This is also on my instructor's recommendation, after he's observed how Hoover responds to me and I respond to him. My instructor has spoken to me about the fact that being too hard can break a horse's nose, but I don't think he would have recommended the move if he thought that was too much of a possibility with Hoover or I.