Chimura vs. Impact

I'm looking at purchasing a medium sized softbox and see that there is a huge price difference between Impact and Chimura.

Does anyone have experience with both brands and is also able to share why there is such a big price difference?

These are the three that I am looking at:
http://www.bhphotovide​o.com …0_Pro_II_Softbo​x_for.html

http://www.bhphotovide​o.com …uxbanx_Softbox_​36x48.html

http://www.bhphotovide​o.com …Photo_Basics_So​ftbox.html

I have 2 large, 2 medium and 2 small Chimera softboxes that I've been using for over 20 years. They've been set up, torn down and packed year after year. When I started using them I had Norman 4000WS packs and heads. I moved on to Balcar, Comet and Profoto lights and just changed speedrings.

I bought 3 Calumet Illuma softboxes a few years ago for a job because they're shallower but still quite even. I've had a couple of wands break, but otherwise they've been great.

Just like the B+W filters and the Gitzos in your gear list, you get what you pay for.