Some of the wheels are better than other. Any wheel with a cross bar construction is not safe. I don't think the Silent Runner is safe. Flyers run very fast on the wheel. Any bar or slots in the open side can cause serious injuries. They will jump out or be thrown out while it is spinning. Bars or slots can break their back or cause other injuries.
I do believe that Attix Worx makes the best wheels. I originally bought a Stealth Wheel. My first flyer NEVER used it. The second flyer LOVES it. He runs like a maniac on the thing. He also though it tasted awesome. He chewed the running track so badly that it was no longer safe. The Magnum wheel is the same as the Stealth except that it has a PVC coated metal track. The company sent me the metal track. I installed it on the Stealth wheel in essence making it a Magnum wheel. That solved the chewing problem. I do feel that it is safe. It's pretty common for a flyer to get it up to speed and then stop running. They hang on and ride it round and round like a carnival ride. It makes me dizzy just watching.
This was the first time I saw the Freedom wheel. There are things I like about it and things that concern me. The one piece construction makes it very easy to clean so that's a bonus. I know that the Attix Worx company is always seeking to make a better wheel. I think this version might have been an attempt make a wheel that is easier to manufacture. A one piece wheel could be made with a mold as opposed to the other wheels that are made with a bucket lid. This mold construction is where my concern comes in. I'm pretty sure that the mold construction dictates the size of the grid in the running track. The 1/4inch grid in the track concern me. My only concern is a tiny flyer leg falling through the grid while running. To be honest with you I can't remember the size of the grid in the Stealth wheel. The coated wire mesh on the Magnum has small openings. The openings in the Stealth were larger than the Magnum but can't remember if they were 1/4inch.
Other than that one concern it looks like a great wheel. Watch for chewing. Given the chance a flyer can turn anything plastic into plastic dust.
It is entertaining to watch them run in a wheel.
Edit: looking at the pic again... those sure are large openings in the running track.