Teaching "drop on recall"?

Are you certain that you want your dog to do this? The decision, of course, is yours-but I feel that training one of my dogs to sit on recall was a huge mistake...now she won't respond to sit unless she is immediately next to me. It's been impossible to break her of this...when we're in the field, and I want her to sit, I want her to sit where she is, not where I am-but she insists on returning to my side first (because that's how I trained her)...this was the biggest training mistake I ever made---just wanted to share my experience with you before you train your dog to do the same. Good luck with your cles.