This has been discussed a thousand times on here. Just do a search.
Heard terrible things about the Belkin. I've got a Caudabe Shell and it's still going strong many months later. http://www.caudabe.com/products/ipad-back-cover-shell-frost
My first Belkin did have the notorious cracked corners. However, they sent me a free replacement within two days. I haven't had any problems with the new one.