@Zande I share your concern about damaging the neck. I only use the Flexi with a harness. I know you're not a fan, but it works for us. The only time I use a Martingale is with a short lead. I've worked many hours with Logan on both long and short leads. He's gotten so much better. He's learned that when he's on the short lead he's working. He also knows that he'll get leeway on the longer lead, but only in certain places. One thing I kept working on with him while on the long lead was recall. Before he'd get to the end I'd call him "Logan, Come!" he'd trot back and get a treat. Now, every time I even begin to say the command he comes right away. I wish Sparkle was as food driven, but she's not when she's outside. She's proving to be more of a challenge for me. I'm determined to prove she's not smarter than me.
I wish I had a forest I could turn him loose in, but we don't have anything like that here. All the county and state parks have leash laws. There's a few state beaches that allow for off leash, but we don't get there very often.