Welcome back to the new NEFF. Take a break from Twitter and Facebook. You don't go to Dicks for your fly fishing gear, you go to your local fly fishing store. Enjoy!
They all look different, thickness anyway. I found Ovis tippet to be more supple and easier to tie knots with. I bought some Wal-Mart tippet once, I forget the brandname...it is terrible compared to all the others.
You can actually spot the difference? The one on the bottom looks to be the strongest. The top is the 7x but the same brand as the one on the bottom. I'm going to compare more of these.