As previously mentioned, the Clinton Anderson rope halters have two additional strategically placed knots that act on pressure points on the horse's nose when you put pressure on the halter. This is a big difference from the regular rope halters. I really find these knots do help out, they help the horse to understand what is being asked from the get-go. The CA halters are also made out of a stiffer rope, which I like. It makes the halter not feel so flimsy. I have a couple of CA halters (from when they weren't so darn expensive!) that have lasted me for several years. I would definitely take a CA halter over a regular one!
I use a regular rope halter with my yearling, and while it works for now, I plan to get him a CA halter soon. While it might be expensive, it will easily last for most of his life!
every ride counts.