CPine,
I don't think this looks like a bad option, one reviewer stated they got steel plated not Stainless Steel bars and sent it back. If you do purchase the one from Amazon I recommend doing the magnet test once it arrives. Nickel is magnetic, 304 SS is not, if it is magnetic I would worry it is not fully 304 SS and if it is not magnetic I think I you are good to go.
I think connected to your other post that Richard responded to, the SnS does not make a grate with a center cut out. There big product is the Slow n Sear so they have the big flip up section.
The big thing I want to say is if you get a 304 SS grate I think the grate will be able to handle the heat of the vortex, no problem, so at that point the removable center is preference based over nessassity for the vortex. If you want to get other center pieces, the CI center, use for a Wok, others that would make sense. If you go steel plated yes you need the removable center for the vortex.
As I started this post I don't think the one from Amazon is a bad option, just not a name I recognize. I will say from personal experience with purchasing a Slow n Sear and from watching all of Richard's great cooks I do trust the quality and products from Slow n Sear, and with the sale on the easy spin grate it is an option that I would highly recommend.