If you read my post #2 you'll see that I'm agnostic on cage length. I also tried to separate what I'd do for myself from what the OP might want to do for himself.

I don't try to convince people to go a certain way, or do as I do. I try to lay out the options, and things to think about then let folks decide for themselves. Also, RDs can be pushed beyond their limits (within reason) and in many cases I'd rather have a shorter cage, even if it meant that my granny couldn't be used with any sprocket smaller than 16t or so.