What's the advantage of the new style vs the old? Does the new style extend at all?
Let me start by saying everyone has their own opinions and preferences for mirror function and cosmetics, so if someone likes the old style, bravo. With that said, they are not for me. The old style mirrors, when folded down, looked good on the truck, but the vertically oriented convex/blindspot mirror was absolutely useless. It's a weird long, narrow teardrop shape that has an odd exaggerated convexity in the vertical position. I tried them like that for a week or two, and had multiple times where I could not see a car in my blind spot. When flipped up, they work well, but 1. look ridiculous, and 2. make the truck so wide that there are places I have to fold them in just to fit through (the truck has power fold for the entire arm, but not power flip up/down). Anyone who has crossed from Charlotte to Belmont on the old US74 bridge knows how narrow it is, and I literally had to fold the mirrors in when I crossed the bridge so they wouldn't hang out into oncoming traffic or hit the sign that is inline with the guardrail on the bridge. Also, they look unfinished or like something is missing when flipped up:
The new ones are a good bit narrower and look intentionally designed. They also have a power telescoping feature (that is NOT plug and play compatible with the older trucks). However, on my Fords, and on my Ram 5500 with Chevy style mirrors, I basically never telescope them out anyway, so I'm not too worried about that. I also never pull a camper or enclosed trailer, so that makes a big difference. The lower trim level mirrors have a manual telescope, so that's a good option if you don't want or need the fancy features such as power convex and blindspot monitoring and surround view camera.
Here's a few pics of them installed in the daylight:
One more comparison: