Either center is strong enough. The Flat guys are 3/8" thick so no worires about bending one. IIRC, the stock hummer rim center is only 3/16" thick and they seem to hold up. I do like the way the pressed centers look though.
It comes down to how much back spacing you need. With the Flat centers, you can go 4.5" BS, for the pressed centeres, you can only go 3.5" BS (This is from talking to TW).
Edit: I R DUM. Slo-vo was talking about Trail Ready, NOT Trail Worthy. Two differnt products/companies. I don't have any experience with Trail Ready, so ignore the above information, (unless you actually meant Trail Worthy).