I have been using Pro Ears "Pro Slim" model for several years. Very sastified with the quality. No experience with the other model you mentioned. Pro Ears do have a 5yr warranty.
I'll put in a vote for the Pro Ears, I got them after listening to several folks here at TFL and I have been very satisfied with them. I opted for the Magnum model since I want as much sound stopping ability as possible - I still like to be able to hear musicians instead of just watching them. This vote, however, is not a vote against the Wolf Ears because I didn't compare them.
I still double plug when at an indoor range, but this isn't necessary outdoors with any boomer I've tried.