Assume the recipient of the pitch knows nothing about you. By starting from scratch, you level the playing field and are assured that no important part of your story will go unheard. Do this even for people that were introduced to you by a close mutual friend.
But perhaps the biggest change driving angels these days is just how much more valuable prorata rights actually are. I believe I was one of the first to point this out publicly. A day after I published this Changing Structure of VC article I noticed at least one “Angel Prorata Fund” on AngelList. So if there are platforms like AngelList that help scoop up the prorata rights of angels in deals like Uber, AirBNB, DropBox (or the future companies like these) then perhaps the prorata fight gets worse.