The Ritter block in it's aluminium form is the same casting as the iron version. It's not a specific pattern, I'm not even sure if they've allowed for the different shrinkage rates of the two materials.
I'd want to see some more material in the casting, ribs etc. That's just a personal preference of mine. I think for most of us, the weight saved in an aluminium block is more of a benefit. Those chasing every last piece of HP, in a car they have to add ballast too, you'd go Iron.