Dennis,
I use the cheaper one I got from Farm & Fleet. I've found the secret to be a square cut on the tube, making sure the die starts and remains square to the tube through the forming, and some brake fluid for lube.
The problems arise when the die starts to angle as it's being tightened. I tighten it very slowly and keep a close eye on it. If it even looks like it's starting to cock, I stop and correct it.
Mind you, this tool only works on the mild steel line, I wouldn't even think of trying stainless.
Bob
