I've never worked with it, but ERC is very pretty. I've also heard that it has a tendency to go "kaboom" now and then, though.
I really like red elm and it's also a good looking wood. A hickory backed red elm board bow was one of my favorites. It was quick, very light in the hand, and only took about a half inch of set. I thought I did a good job tillering it, but after a couple of weeks it started to chrysal in just one spot, 10" from the tip of the top limb. I'll be making another soon.
Good luck on your bow!