EGR differences

[Chrispbrown36]

Looking at what is out there and I noticed a few things. First, I noticed that they are listed for automatic and manual transmissions. Anyone know why there would be a difference there? Second, AC Delco (same with the off brands) show two different styles. One style has a solid top with the nipple you attach the hose onto formed into the top. The other has a plastic nipple that rotates. The first style seems better to me simply because the rotating plastic piece seems like it would break or get damaged easily. Am I putting too much thought into this? For what they are they are pretty pricey.