Does anyone know if there is another company than PorterCase that makes a similar case/dolly?

I've had mine for over a year now and kind of have a love-hate relationship with it but I can't seem to be able to find any other model out there that offers the same versatility

Porter Case - /main/product_info.php?products_id=73 (http://portercase.com/main/product_info.php?products_id=73)

PorterCase PCi Case - YouTube